Officer Nick-Tomasito Birco, 39, a five-year veteran of the force assigned to Bayview Station, responded to the chase in the Portola District early the morning of July 26, 2006.
At about 1 a.m., the van, driven by Steven Petrilli, of San Francisco, ran a stop sign at Cambridge and Felton streets and struck Birco's car. Birco was pronounced dead at the hospital.
According to prosecutors, police had linked the van to four street robberies that had occurred in the city earlier that night, and spotted it after the last robbery in the Bayview District.
Petrilli's attorney has argued that he was an unwilling participant in the robberies and had been threatened by the two other men in the van who had committed them.
The two other men are also awaiting trial for murder.
The closing arguments got under way at about 10 a.m. in San Francisco Superior Court.
