Court rulings explained in plain English for pro per/pro se defendants and their families
Criminal Defense Resources™ is a free, searchable library of real criminal court rulings for people representing themselves (pro per/pro se) and the families supporting them, anywhere in the United States. It covers landmark U.S. Supreme Court decisions plus federal appeals court and state court rulings, with more courts and states added over time.
Every ruling links to the full official or public opinion.
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State v. Coleman
The court held that a trial judge did not abuse its discretion by admitting a DNA report made with STRmix software, a probabilistic genotyping program. The report said the DNA on shell casings was at least 28 times more likely, and the DNA on a gun magazine and bullets at least 8,000 times more likely, to include the defendant than not. The court said low likelihood ratios are not a reason to exclude DNA evidence when they still support inclusion. Because the analyst explained the statistics, the jury could decide how much weight to give them, so the evidence was relevant and not unfairly prejudicial. The convictions and sentences were affirmed.
Chatrie v. United States
The Court held that police conducted a Fourth Amendment search when they obtained a person's Google Location History data through a geofence warrant, because people have a reasonable expectation of privacy in their cell-phone location information. The Court did not decide whether this particular multi-step warrant was valid; it vacated the Fourth Circuit's decision and sent the case back for that court to decide.
United States v. Chatrie
The full Fourth Circuit affirmed the conviction in a one-sentence unsigned opinion. The judges were evenly divided on whether obtaining the geofence data was a Fourth Amendment search. The U.S. Supreme Court later vacated this decision in Chatrie v. United States (2026).
United States v. Smith
The Fifth Circuit held that geofence warrants are modern-day general warrants that violate the Fourth Amendment. But it did not suppress the evidence in that case, because officers relied in good faith on the warrant.
United States v. Chatrie
A divided Fourth Circuit panel held that no search occurred because the defendant did not have a reasonable expectation of privacy in two hours of Location History data he had voluntarily shared with Google. The full court later reheard the case.
Erlinger v. United States
The Court held that, under the federal Armed Career Criminal Act, whether a defendant's past offenses happened on separate "occasions" must be decided by a unanimous jury beyond a reasonable doubt (or admitted by the defendant), not decided by a judge.
State v. Schoenhardt
In an aggravated assault case where the defendant claimed self-defense, the Arizona Court of Appeals upheld the trial judge's decision to keep out the defense's use-of-force expert, a former police officer with 20 years of experience. The court said the expert's opinions that the defendant's display of a gun was justified and that the other man was the real aggressor were not relevant, because neither person was a police officer, and because experts may not tell jurors how to decide the case. The expert's criticism of the police investigation (not interviewing one witness and not separating witnesses) was properly excluded as a waste of time because it repeated points the jury already heard: the officer testified that separating witnesses and talking to all of them is good police practice, admitted he did not interview that witness, and defense counsel criticized him for not following those practices. Because the issue was raised for the first time on appeal, the court reviewed only for fundamental error.
Vega v. Tekoh
The Court held that a violation of the Miranda rules, by itself, does not give a person the right to sue an officer for money damages under the federal civil rights law (42 U.S.C. section 1983).
State v. Pickett
The court held that if the State uses an expert who relies on novel probabilistic genotyping software (here, TrueAllele) for DNA testimony, the defendant is entitled to the software's source code and related development records, such as testing, design, bug reports, and change logs, under a protective order, to challenge its reliability at a Frye hearing. The defendant must first show a "particularized need" for that discovery. The court reversed the trial judge's denial and told the judge to order the discovery under a protective order.
State v. Mixton
The Arizona Supreme Court held that neither the Fourth Amendment nor the Arizona Constitution's private affairs clause requires a warrant for police to obtain a person's IP address or internet subscriber information from a service provider.
State v. Soto-Fong
The Arizona Supreme Court held that consecutive prison sentences for multiple crimes committed as a juvenile do not violate the Eighth Amendment, even when the total exceeds the person's life expectancy, because the U.S. Supreme Court's juvenile-sentencing cases address sentences for single crimes.
United States v. Valencia-Lopez
The Ninth Circuit vacated a defendant's four drug convictions and ordered a new trial because the district court let a government expert, an ICE supervisory special agent, testify without making any finding that his key opinion was reliable. The defendant said armed men forced him to drive drugs across the border; the agent testified the chance that traffickers would trust drugs to a coerced driver was "almost nil." The court said the agent's experience was enough to qualify him as an expert, but the record did not show why that experience made this particular opinion reliable, and brushing off objections as "going to the weight" is not a reliability ruling. One judge dissented.
Krause v. County of Mohave
In a civil lawsuit over a deputy's fatal shooting, a federal trial court in Arizona limited the plaintiff's police-practices expert. He could not offer legal conclusions, such as that the force was "not objectively reasonable" or that elements of a legal claim were met. He could not give ballistics or bullet-trajectory opinions, because his police, firearms, and gunsmith experience did not qualify him in that technical field, and he could not testify about medical matters. A new opinion he first gave at his deposition, months after the disclosure deadline, was excluded as untimely. The court found him qualified as a police-practices and use-of-force expert and allowed his testimony on whether deputies violated sheriff's office policies and accepted police practices, short of legal conclusions.
State v. Simmer
The court held that the trial judge did not abuse its discretion by admitting DNA analysis done with TrueAllele probabilistic genotyping software over the defendant's Daubert/Schafersman challenge to its reliability. It also held that a low mixture weight (a small share of the defendant's DNA in a mixture), which makes the match statistic less certain, is not a reason to exclude the evidence. That goes to weight for the jury, as long as the jury gets the statistical context. The court cautioned that its opinion does not mean TrueAllele evidence must be admitted in every future case.
United States v. Cano
The Ninth Circuit held that at the border, officers may do a manual search of a cell phone without suspicion, but a forensic (device-copying) search requires reasonable suspicion. It also held that border phone searches are limited to looking for digital contraband.
Garza v. Idaho
The Court held that when a lawyer ignores a defendant's instruction to file a notice of appeal, harm is presumed, even if the defendant signed a plea agreement that waived some appeal rights.
Carpenter v. United States
The Court held that when the government obtains a person's historical cell-site location records from a phone company, that is a Fourth Amendment search, and police generally need a warrant.
McCoy v. Louisiana
The Court held that a defendant has the right to insist that his lawyer not admit guilt at trial, even when the lawyer believes admitting guilt is the best way to avoid a death sentence. Violating that choice is a "structural" error that requires a new trial without any separate showing of harm.
Rascon v. Brookins
In a civil lawsuit against Phoenix police officers over a man's death, a federal trial court in Arizona limited the plaintiffs' police expert, Roger Clark, to law enforcement use of force, training, procedures, and administration. He could not give medical opinions, including on cause of death or the physiological effects of a TASER, which the plaintiffs conceded he was not qualified to give. He could testify about whether the force, including the TASER, was justified and that officers should have acted differently, but could not say the officers acted unconstitutionally or used excessive force, because those are legal conclusions. The same order limited or excluded several other experts.
Simpson v. Miller
The Arizona Supreme Court held that Arizona's rule denying bail to everyone charged with sexual conduct with a minor under 15, when the proof is evident or presumption great, violated due process because it did not require an individualized finding that the person is dangerous.
State v. Peoples
The Arizona Supreme Court held that a person has a reasonable expectation of privacy in the contents of his cell phone, even when the phone is left in someone else's home, and that a warrantless search of the phone violated the Fourth Amendment.
United States v. Lambis
A federal trial court in New York held that agents' use of a cell-site simulator, without a warrant, to find a phone inside a specific apartment was an unconstitutional search, and it suppressed the evidence found as a result.
Lynch v. Arizona
In a short unsigned opinion, the Court held that when a capital defendant's future dangerousness is at issue and the only alternative to death is life without parole, the defendant is entitled to tell the jury he would not be eligible for parole. The possibility of future clemency or law changes does not remove that right.
United States v. Graham
The full Fourth Circuit held that the government's acquisition of historical cell-site records from a phone company was not a Fourth Amendment search, applying the third-party doctrine.
State v. Valenzuela
The Arizona Supreme Court held that a DUI arrestee's consent to a blood or breath test is not voluntary under the Fourth Amendment when it follows an officer's statement that Arizona law requires the person to submit. In this case, the evidence was not suppressed because officers had relied in good faith on court decisions in effect at the time.
State v. Andrews
The Maryland Court of Special Appeals held that people have a reasonable expectation that their cell phones will not be used as real-time tracking devices by police, and that using a cell-site simulator to locate a phone requires a warrant based on probable cause. An order under the pen register statute was not enough, and the evidence was suppressed.
United States v. Davis
The full Eleventh Circuit held that obtaining historical cell-site records from a phone company with a court order under the Stored Communications Act, rather than a warrant, did not violate the Fourth Amendment.
State v. Bernstein (Herman)
In a special action brought by the State in eleven aggravated DUI cases (the real parties were Doreen Lynn Herman and ten other defendants), the Arizona Supreme Court held that under Arizona Rule of Evidence 702(d), the trial judge, as gatekeeper, must consider whether an expert correctly applied a reliable method to the facts of the case. But mistakes in applying a method justify excluding the evidence only if they make the results themselves unreliable; otherwise the jury weighs them. The trial judge had excluded blood-alcohol results because the lab's gas chromatograph sometimes failed to produce results and had other problems. The Supreme Court said that applied the wrong standard, because the record did not show the defendants' own results were unreliable, and vacated the exclusion order.
Grady v. North Carolina
In a short unsigned opinion, the Court held that a state program that attaches a satellite-based (GPS) monitoring device to a person's body to track the person's movements is a Fourth Amendment search. It sent the case back for the state courts to decide whether the search was reasonable.
Lopez-Valenzuela v. County of Maricopa
The full Ninth Circuit held that Arizona's Proposition 100 laws, which denied bail to all undocumented immigrants charged with a wide range of felonies, violated due process because they were not narrowly tailored and did not provide individualized decisions.
State v. Glissendorf
The Arizona Supreme Court explained when a defendant is entitled to a Willits instruction: the defendant must show that the State failed to preserve material and reasonably accessible evidence that could have had a tendency to exonerate the accused, and that this caused prejudice. The defendant does not have to prove that the lost evidence would actually have cleared him. In this case a detective's recorded interview of the accuser had been lost, the trial court refused the instruction, and because the State could not show the error was harmless, the court reversed the convictions.
Riley v. California
The Court held that police generally must get a warrant before searching the digital contents of a cell phone taken from a person who has been arrested.
Commonwealth v. Augustine
The Massachusetts Supreme Judicial Court held that under the Massachusetts Declaration of Rights, the government must get a search warrant based on probable cause before obtaining two weeks of a person's historical cell-site location information from a phone company.
State v. Earls
The New Jersey Supreme Court held that under the New Jersey Constitution, police must generally get a warrant before obtaining cell-phone location information from a service provider.
Maryland v. King
The Court held that when officers arrest someone for a serious offense with probable cause and bring the person to the station, taking a DNA cheek swab is a legitimate booking procedure that is reasonable under the Fourth Amendment, like fingerprinting and photographing.
United States v. Olsen
The Ninth Circuit found that the government did not disclose information about problems with a state crime lab forensic scientist who worked on the case. But the court held the information was not "material" given the other evidence, so the conviction was affirmed.
Missouri v. Frye
The Court held that defense lawyers generally have a duty to tell their clients about formal plea offers from the prosecution that may be favorable. Failing to do so can be ineffective assistance of counsel.
State v. Sosnowicz
In a second-degree murder case where the defense was that running over the victim with a vehicle was an accident, the Arizona Court of Appeals held that the medical examiner should not have been allowed to testify that the manner of death was "homicide." He admitted the classification rested on what police told him, not on specialized medical knowledge, so he was in no better position than the jury to decide accident versus homicide, and jurors could take his opinion to mean the defendant was guilty. The court said a manner-of-death opinion based mainly on the autopsy will often be admissible, while one based largely on witness accounts the jury can judge for itself normally will not be. Because the other evidence was very strong, the error was harmless and the convictions were affirmed.
United States v. Jones
The Court held that the government's installation of a GPS tracking device on a person's vehicle, and its use to monitor the vehicle's movements, was a search under the Fourth Amendment.
Perry v. New Hampshire
The Court held that the Due Process Clause requires a preliminary judicial check on the reliability of an eyewitness identification only when the police arranged the suggestive circumstances. Other suggestive circumstances are left to safeguards such as cross-examination and jury instructions.
Doody v. Ryan
The full Ninth Circuit held that a 17-year-old's confession, given after a lengthy overnight interrogation in an Arizona murder investigation, was obtained in violation of Miranda because the warnings were confusing and played down, and that the confession was involuntary. Federal habeas relief was granted.
Skinner v. Switzer
The Court held that a convicted prisoner seeking DNA testing of crime-scene evidence may bring that claim as a federal civil rights lawsuit under 42 U.S.C. section 1983, rather than only through habeas corpus.
State v. Sweeney
The Arizona Court of Appeals held that after a traffic stop ended, an officer needed reasonable suspicion to hold the driver longer for a drug-dog sniff. Because there was no reasonable suspicion for that second detention, it was unlawful.
District Attorney's Office for the Third Judicial District v. Osborne
The Court held that there is no freestanding federal constitutional right to obtain evidence for post-conviction DNA testing, and that the state's procedures for post-conviction relief were adequate.
Arizona v. Gant
The Court held that police may search a car after arresting a recent occupant only if the arrested person could reach into the passenger area at the time of the search, or if it is reasonable to believe the car contains evidence of the crime of arrest.
United States v. Craighead
The Ninth Circuit held that questioning in a person's own home can be "custodial" for Miranda purposes when the setting is police-dominated. Courts look at factors such as how many officers were there, whether they were armed, whether the person was restrained or isolated, and whether he was told he was free to leave.
Indiana v. Edwards
The Court held that a state may require a lawyer for a defendant who is competent to stand trial but who, because of severe mental illness, is not competent to conduct the trial on his or her own.
Smith v. City of Hemet
In a civil excessive-force lawsuit, the full Ninth Circuit held that the plaintiff's earlier conviction for resisting or obstructing an officer did not automatically bar his lawsuit, because the force may have been used after the conduct behind the conviction. It also defined "deadly force" as force that creates a substantial risk of causing death or serious bodily injury, and reversed summary judgment for the officers. In deciding the force issue could not be resolved without a trial, the court noted that the plaintiff offered an expert declaration, based on California's Peace Officer Standards and Training, that officers could have used control holds instead of a police dog, and said a rational jury could rely on such evidence. It cited Larez v. City of Los Angeles, 946 F.2d 630 (9th Cir. 1991), and Davis v. Mason County, 927 F.2d 1473 (9th Cir. 1991), for police-practices expert testimony.
Hangarter v. Provident Life & Accident Insurance Co.
In a civil insurance bad-faith case, the Ninth Circuit upheld admission of an insurance-industry expert who testified that the insurer departed from industry standards. The court explained that an expert cannot give a legal conclusion (an opinion on an ultimate issue of law), but this expert never said the insurer acted in bad faith; he testified about industry standards, which supported that finding without stating it. The court also held that for non-scientific testimony like this, Daubert factors such as peer review and error rates may not apply, because reliability depends on the expert's knowledge and experience. The trial judge wrongly said Daubert did not apply at all, but that was harmless because the judge had probed the expert's experience.
Crawford v. Washington
The Court held that "testimonial" out-of-court statements from a witness who does not testify at trial cannot be used against the defendant unless the witness is unavailable and the defendant had a prior opportunity to cross-examine that witness.
United States v. Erskine
The Ninth Circuit held that a defendant's decision to give up his lawyer and represent himself was not knowing and intelligent, because the record showed he had not been correctly informed of the maximum penalty he faced. The conviction was reversed.
Wiggins v. Smith
The Court held that defense lawyers violated the Sixth Amendment right to effective counsel at a capital sentencing when they did not investigate the defendant's background beyond a presentence report and social services records. Their choice not to prepare a social history fell short of professional standards, and it prejudiced the defense.
Ring v. Arizona
The Court held that Arizona's death-penalty system, which let a judge alone find the aggravating factors needed for a death sentence, violated the right to a jury trial. A jury must find those factors.
State v. Spreitz
The Arizona Supreme Court held that claims of ineffective assistance of counsel should be raised in post-conviction relief proceedings (under Arizona Rule of Criminal Procedure 32), not on direct appeal. Appellate courts will not decide those claims on direct appeal.
Apprendi v. New Jersey
The Court held that, other than a prior conviction, any fact that raises the penalty for a crime beyond the maximum set by law must be decided by a jury and proved beyond a reasonable doubt.
United States v. Hankey
In a drug case, the Ninth Circuit upheld letting a police gang expert testify, to show possible bias in a co-defendant's testimony, that members of affiliated gangs who testify against each other are beaten or killed. The court said the Daubert factors (testing, peer review, error rates) did not fit this kind of testimony, whose reliability depends on the expert's knowledge and experience, and that trial judges have broad discretion in how they test reliability. The trial judge had held a hearing, questioned the officer about the basis for his opinions, refused to let him testify about one witness's gang membership for lack of foundation, and gave the jury a limiting instruction.
Martinez v. Court of Appeal of California, Fourth Appellate District
The Court held that the Faretta right to self-representation does not extend to a direct appeal. The Constitution does not require states to let a defendant represent himself on appeal from a criminal conviction.
Kumho Tire Co. v. Carmichael
In a civil tire-failure case, the U.S. Supreme Court held that the trial judge's Daubert gatekeeping duty applies to all expert testimony, including testimony based on technical or other specialized knowledge and on experience, not just scientific testimony. The judge may use the Daubert factors when they help measure reliability, but they are not a required checklist, and the judge has broad latitude in deciding how to test reliability. The Court upheld the exclusion of a tire expert whose method, as applied to this tire, was not shown to be reliable.
United States v. Scheffer
The Court held that Military Rule of Evidence 707, which bars all polygraph evidence in court-martial proceedings, does not violate an accused's constitutional right to present a defense. The Court pointed to the lack of scientific consensus on whether polygraph results are reliable.
State v. Salazar
The Arizona Court of Appeals upheld the exclusion of a defense expert who would have testified that there was a "90 percent" likelihood that a person inexperienced with firearms would be disarmed by an attacker if he tried to use the gun in self-defense. The court saw no connection between that opinion and the defendant's actions or his claimed belief that deadly force was necessary, since there was no evidence he fired because he feared being disarmed. It also said that whether self-defense was reasonable is generally a question for jurors' common sense, so expert testimony on that issue is generally not allowed. The conviction was still reversed for other reasons: the trial judge should have been disqualified, and the defense was wrongly barred from asking two State witnesses about their juvenile probation status to show possible bias.
Kyles v. Whitley
The Court held that whether suppressed evidence is "material" depends on the combined effect of all the withheld evidence, not each item alone. The prosecutor has a duty to learn of favorable evidence known to others acting for the government, including the police.
Daubert v. Merrell Dow Pharmaceuticals, Inc.
In a civil case claiming a prescription drug caused birth defects, the U.S. Supreme Court held that the Federal Rules of Evidence, not Frye's "general acceptance" test, govern expert scientific testimony in federal trials. The trial judge must act as a gatekeeper and make sure the testimony rests on a reliable foundation and fits the issues in the case. Factors the judge may consider include whether the theory or technique can be and has been tested, peer review and publication, the known or potential error rate and standards controlling the technique, and general acceptance. The inquiry is flexible and focuses on methods, not conclusions.
Doggett v. United States
The Court held that an eight-and-a-half-year delay between indictment and arrest, caused by the government's negligence, violated the right to a speedy trial, even though the defendant could not point to specific harm to his defense.
Arizona v. Youngblood
The U.S. Supreme Court held that when police fail to preserve evidence that is only potentially useful to the defense, there is no violation of federal due process unless the defendant can show the police acted in bad faith. In this case, police did not refrigerate clothing or test samples in time, which the Court described as at worst negligent, so the Arizona Court of Appeals' reversal of the conviction was itself reversed.
United States v. Salerno
The Court upheld the federal Bail Reform Act of 1984, which allows a court to hold an arrested person before trial if the government shows by clear and convincing evidence that no release conditions will reasonably protect others and the community.
Batson v. Kentucky
The Court held that the Equal Protection Clause bars a prosecutor from using peremptory strikes to remove potential jurors because of their race. A defendant can make a prima facie case from the facts of the defendant's own trial. Then the prosecutor must give a race-neutral explanation for the strikes.
State v. Lindsey
The Arizona Supreme Court held that an expert may explain general behavior patterns of child sexual-abuse victims to help jurors weigh testimony, but may not give an opinion on whether a particular witness is truthful, on the truthfulness of witnesses of that type, or on the percentage of such witnesses who tell the truth. Here the State's expert said most people in her field believe very few incest victims lie and that the likelihood was "very strong" in this case. The court said "the law does not permit expert testimony on how the jury should decide the case," reversed the two incest convictions, and ordered a new trial on those counts. The other convictions were affirmed, but a later supplemental opinion sent them back for resentencing.
Ake v. Oklahoma
The Court held that when a defendant makes a preliminary showing that his sanity at the time of the offense is likely to be a significant factor at trial, the Constitution requires the state to provide access to a psychiatrist's help if the defendant cannot otherwise afford one.
United States v. Karo
The Court held that monitoring a beeper inside a private home, in a place not open to visual surveillance, is a Fourth Amendment search that generally requires a warrant.
Strickland v. Washington
The Court set a two-part test for claims that a defense lawyer was ineffective. First, the lawyer's performance fell below an objective standard of reasonableness. Second, there is a reasonable probability the result would have been different without the lawyer's errors.
McKaskle v. Wiggins
The Court held that a judge may appoint standby counsel for a self-represented defendant, even over the defendant's objection. But standby counsel may not take over. The defendant must keep actual control over the case presented to the jury, and the jury must still see the defendant as representing himself.
United States v. Knotts
The Court held that using a radio beeper to follow a car on public roads was not a Fourth Amendment search, because a person traveling on public roads has no reasonable expectation of privacy in movements others could see.
Edwards v. Arizona
The Court held that once a person in custody asks for a lawyer, police must stop questioning until a lawyer is present, unless the person himself starts further conversation with police.
Franks v. Delaware
The U.S. Supreme Court held that a defendant may challenge the truth of statements in a search warrant affidavit. If the defendant makes a substantial preliminary showing that the officer who swore to the affidavit included a false statement knowingly and intentionally, or with reckless disregard for the truth, and the statement was necessary to the finding of probable cause, the court must hold a hearing. If the defendant proves this at the hearing and the rest of the affidavit does not establish probable cause, the warrant is voided and the evidence from the search is excluded.
Manson v. Brathwaite
The Court held that reliability is the "linchpin" in deciding whether an identification made after a suggestive procedure can be used. Courts weigh the Biggers factors against the corrupting effect of the suggestive procedure, rather than automatically excluding the identification.
Faretta v. California
The U.S. Supreme Court held that the Sixth Amendment gives a person charged with a crime the right to represent himself or herself. A state cannot force a lawyer on a defendant who knowingly and intelligently chooses to go without one.
Neil v. Biggers
The Court held that even when police use a suggestive identification procedure, the identification may still be used if it is reliable under the totality of the circumstances. It listed factors: the witness's opportunity to view the person, the witness's degree of attention, the accuracy of any earlier description, the witness's level of certainty, and the time between the crime and the identification.
Barker v. Wingo
The Court held that the constitutional right to a speedy trial has no fixed deadline. Instead, courts weigh four factors: how long the delay was, the reason for it, whether and when the defendant asserted the right, and whether the delay harmed the defendant.
Giglio v. United States
The Court held that the prosecution's duty to disclose includes evidence that affects a key witness's credibility, such as a promise of leniency in exchange for testimony. A promise made by one prosecutor is charged to the whole prosecutor's office.
Britt v. North Carolina
The Court named two factors for deciding whether a defendant who cannot pay needs a free transcript: (1) the value of the transcript for the appeal or trial, and (2) whether other options would do the same job. On the facts of this case, the Court found the transcript of an earlier mistrial was not needed, because other options were available.
State v. Dessureault
The Arizona Supreme Court held that when a defendant challenges a pretrial identification, the trial court should hold a hearing outside the jury's presence. The State must show by clear and convincing evidence that the pretrial identification was not unduly suggestive, and if it was, that any in-court identification is not tainted by it.
Terry v. Ohio
The Court held that a police officer may briefly stop a person when the officer has reasonable suspicion, based on specific facts, that criminal activity may be happening. If the officer reasonably believes the person is armed and dangerous, the officer may do a limited pat-down of outer clothing for weapons.
Katz v. United States
The Court held that the government's recording of a man's conversation in a public phone booth, without a warrant, was a search under the Fourth Amendment. The Fourth Amendment protects people, not just places.
United States v. Wade
The Court held that a post-indictment lineup is a critical stage of the prosecution at which the defendant has a right to have a lawyer present. A later in-court identification may still be allowed if the prosecution shows it has a source independent of the improper lineup.
Miranda v. Arizona
The Court held that statements made during custodial police interrogation cannot be used against the defendant unless police first give warnings: the right to remain silent, that statements can be used in court, the right to a lawyer, and that a lawyer will be appointed if the person cannot afford one.
State v. Willits
The Arizona Supreme Court held that the trial judge should have given the jury an instruction the defense asked for: if the jury found that the State had destroyed or failed to keep evidence, it could infer that the evidence would have been unfavorable to the State. Because the instruction was refused, the court reversed the conviction and sent the case back for a new trial.
Brady v. Maryland
The Court held that when the prosecution suppresses evidence favorable to the accused that was requested, it violates due process if the evidence is material to guilt or punishment. This is true whether the prosecutor acted in good faith or bad faith.
Gideon v. Wainwright
The Court held that the right to a lawyer is a fundamental right that applies in state courts. States must provide a lawyer to people charged with felonies who cannot afford one.
Mapp v. Ohio
The Court held that evidence obtained through an unconstitutional search and seizure cannot be used in state criminal trials. This applied the "exclusionary rule" to the states.
Griffin v. Illinois
The Court held that a state that grants appellate review cannot deny it to a defendant just because the defendant cannot afford a trial transcript. The lead opinion said, "There can be no equal justice where the kind of trial a man gets depends on the amount of money he has."
Stack v. Boyle
The Court held that bail set higher than an amount reasonably calculated to make sure the defendant shows up for trial is "excessive" under the Eighth Amendment. Bail must be based on standards tied to that purpose and to the individual defendant.
Frye v. United States
The court affirmed a second-degree murder conviction and upheld the exclusion of a defense expert who would have testified about the results of a "systolic blood pressure deception test" (an early forerunner of the polygraph) given to the defendant. The court said that expert testimony based on a scientific principle is admissible only if the principle is "sufficiently established to have gained general acceptance in the particular field in which it belongs," and this test had not.
Rulings are listed by decision date, newest first. 92 rulings so far, each checked against public court records. More are added over time.