Surveillance tapes obtained by News 12 Westchester show the chain of events that led up to the death of an off-duty Mount Vernon police officer.

On the tapes, Officer Christopher Ridley is shown in a white sedan on Martine Avenue, apparently waiting for someone on Jan. 25, 2007. Shortly after Ridley arrived, a man in the crosswalk is attacked by Anthony Jacobs, a homeless man who later pleaded guilty to the assault and was sentenced to six years in prison.

A Good Samaritan is then seen on the video pushing Jacobs away from his victim, and shortly thereafter Ridley begins to pursue Jacobs.

Ridley tracks Jacobs down, and the video apparently shows the two men in a scuffle on the ground outside the Westchester County Department of Social Services at 85 Court St. At this point two Westchester County officers, Christian Guttierez and Frank Oliveri, are apparently seen shouting at Ridley to put the weapon he was carrying down.

Two other officers, Robin Martin and Jose Calero, then come out of 85 Court St. The four officers are then apparently seen firing their weapons simultaneously at Ridley, who comes up from the ground with the gun seemingly in his hand.

Authorities have argued the four Westchester County police officers fired on Ridley after he did not respond to orders to put the gun down and failed to identify himself as an officer. The county officers were later cleared of any wrongdoing by a grand jury.

Ridley's father, Stanley Ridley, filed a $90 million lawsuit Monday against Westchester County that challenges the grand jury's finding. The lawsuit claims Westchester DistrictAttorney Janet DiFiore is leading a cover-up of the circumstances that led to Officer Ridley's death.

The suit also claims that Officer Frank Oliveri put his gun to Ridley's head and fired at point-blank range after Ridley had already been shot.