New, critical evidence was introduced in the case against a Mount Kisco cop Friday?evidence that prosecutors say proves the defendant was at the scene of the crime.

George Bubaris, who quit the force after the alleged incident, is accused of beating up illegal immigrant Rene Perez and dumping him on the side of Byram Lake Road to die in April 2007. On Friday, a surveillance tape was introduced as evidence that prosecutors say proves Bubaris was on Byram Lake Road at the time Perez was found unconscious.

The tape comes from two cameras on the estate of Nelson Peltz, who lives on Byram Lake Road in Bedford. The footage shows Bubaris? squad car driving down the dark road around the time Perez, who was drunk, was found dying, the prosecution says.

Video footage from a third camera also surfaced this week, and residing Judge Adler has determined that the jury will be watching the footage.

Bubaris is charged with manslaughter after allegedly telling another officer he went hunting for Perez, and dropped him off on Byram Lake Road. According to the autopsy, Perez died from internal bleeding caused by a direct blow to the abdomen?a blow that prosecutors say was delivered by Bubaris.

A Westchester County forensic scientist who tested Bubaris? squad car for evidence also testified Friday. She determined that there was no trace of Perez in the car because the materials on Perez?s clothing were not able to shed.

Detective Sgt. Jeff Dickan, the lead detective in the case, is expected to testify in the future. Testimony will resume on Monday.

Examiner says immigrant died from 'catastrophic' blow