The murder trial for an NYPD officer accused of fatally shooting a Brooklyn man starts today.

Officer Wayne Issacs is set to appear in Brooklyn Supreme Court later this morning.

He allegedly shot and killed 37-year-old Delrawn Small last year on the 4th of July in Cypress Hills.

Police say the two got into a dispute at a red light.

Isaacs, who was off-duty, says Small got out of his car and punched him in the face through his car window before the shooting, but surveillance video shows Small was shot right as he approached Isaacs' window.

Isaacs is charged with second degree murder.

His case is the first being led by the state-appointed attorney tasked with prosecuting deadly shootings by police officers.