A lawyer's mental impressions are almost never evidence and out-of-court statements of witnesses are generally inadmissible hearsay.
Established in Weeks v. United States (1914), this rule holds that evidence obtained through a Fourth Amendment violation is generally inadmissible at criminal trials.
In contradistinction to an image fostered by popular fiction, the police saw themselves as particularly vulnerable to accusations of partiality, the evidence they gathered was generally inadmissible, and the state rarely prosecuted of its own volition.
In law, evidence turned up in an illegal search would generally be inadmissible in court.
U.S. courts and German courts, both of which currently are hearing 9/11-related terrorism cases, generally consider confessions inadmissible if they were coerced.
There is, however, no contemporary evidence of this love affair, before Darnley's death, except the highly dubious so-called Casket Letters, poems and letters supposedly written by Mary to Bothwell but now generally considered to be inadmissible evidence by historians.
The jury was not permitted to hear this evidence because of the legal principle that the accused in a criminal case is to be tried only for the crime charged, not for his character or other conduct; "prior bad acts" are generally supposed to be inadmissible as evidence.
D.C. 46, 47, 293 F. 1013, 1014 (1923), the court stated that expert opinion based on a scientific technique is inadmissible unless the technique is "generally accepted" as reliable in the relevant scientific community.
But polygraphy, which measures blood pressure, breathing rate and perspiration while a series of questions is asked, is generally considered so unreliable that its results are inadmissible as proof in court.
Handwriting analysis is not generally deemed scientifically sound enough to be considered solid evidence and has been deemed inadmissible in the past – including during the trial of Timothy McVeigh, the Oklahoma City bomber.
It is because the inference from "This pile of sand is a heap", and "That pile of sand is slightly larger than this one, and arranged roughly the same way," to "That pile of sand is a heap" is generally acceptable that precisifications which make the premises true and the conclusions false are inadmissible.
