Surveillance videos are often used as evidence in criminal trials.
However, witnesses cannot always watch the video in front of jurors and point out who’s who on the screen.
For a witness to identify someone shown in a video, that witness must have adequate prior knowledge of the person being singled out.
According to the Supreme Judicial Court (SJC) in Commonwealth v. Pina,
The general rule is that a witness’s opinion concerning the identity of a person depicted in a surveillance photograph is admissible if there is some basis for concluding that the witness is more likely to correctly identify the defendant from the photograph than is the jury. Put another way, such testimony is admissible . . . when the witness possesses sufficient relevant familiarity with the defendant that the jury cannot also possess.
Such an identification could make or break the prosecutor’s case.
So if you’ve been charged with a crime and the evidence against you includes surveillance footage, you’d better short this issue out before trial.
This is typically done using a motion in limine seeking to preclude witnesses from making such identifications.