Also known as: forensic evidences · scientific evidence · crime lab evidence
Written by attorneys · grounded in primary & secondary sources — see below
Scientific or technical evidence obtained through forensic methods and offered in court to prove or disprove facts in dispute. Courts evaluate its admissibility by assessing relevance and reliability under flexible standards that may include testing, peer review, error rates, controlling standards, and general acceptance in the field.
Francesca Fowler sued Fusion Power after her home suffered unexplained electrical damage. Fusion offered an engineer who concluded that faulty wiring caused the harm based on a novel arc-mapping technique. The court reviewed whether the method had been tested, published, or accepted in engineering circles before allowing the testimony.
Fatima Flores faced drug charges after police seized pills from her vehicle. The prosecution introduced certificates from a state lab analyst stating the pills contained a controlled substance. Flores objected that the analyst did not appear at trial, requiring the state to produce the witness for cross-examination.
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Felicia Fuentes was charged with robbery after a store clerk identified her in a stationhouse viewing. The prosecution sought to introduce forensic fiber analysis linking her clothing to the scene. The defense challenged the fiber method's error rate and peer-review record before the court allowed the evidence.
Fernando Farrell was prosecuted for assault after blood found at the scene matched his profile. The government introduced DNA results from a private lab. Farrell challenged the sample handling procedures and sought to exclude the match on reliability grounds.
Finn Fletcher stood trial for theft. During voir dire the prosecutor used peremptory strikes to remove all male venire members. Fletcher objected that the strikes rested on gender stereotypes rather than case-specific reasons tied to the forensic DNA evidence expected at trial.
Felipe Figueroa sought to introduce polygraph results showing he told the truth during an interview about a workplace theft at Foxfire Biotech. The government moved to bar the results, arguing the technique lacked sufficient scientific foundation for admission.
Federal courts act as gatekeepers under Rule 702 to ensure expert testimony based on forensic evidence is both relevant and reliable. Reliability is assessed flexibly by considering whether the underlying theory or method has been tested, subjected to peer review, has a known error rate, maintains controlling standards, and enjoys general acceptance in the field.
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A state may not apply an evidentiary rule that categorically bars a defendant from introducing evidence that a third party committed the crime whenever the prosecution's forensic evidence strongly indicates the defendant's guilt.
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A state may not apply an evidentiary rule that categorically bars a defendant from introducing evidence that a third party committed the crime whenever the prosecution's forensic evidence strongly indicates the defendant's guilt. Excluding third-party-guilt evidence solely because of the perceived strength of the state's case violates the defendant's right to present a defense.
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A state may not apply an evidentiary rule that categorically bars a defendant from introducing evidence that a third party committed the crime whenever the prosecution's forensic evidence strongly indicates the defendant's guilt.
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…basis for a State to treat interracial marriages differently from other marriages. On this question, the State argues, the scientific evidence is substantially in doubt and, consequently, this Court should defer to the wisdom of the state legislature in adopting its policy of discouraging interracial marriages. Because we reject…