The funeral mass for officer Arthur Lopez was being held Saturday at St. Christopher's Roman Catholic Church, in Baldwin.
Lopez was shot to death Tuesday after he pulled over a car he believed had been involved in a hit-and-run accident.
Police say that after Darrell Fuller killed the officer, he allegedly murdered an innocent motorist, Raymond Facey, before stealing his car.
Fuller was charged with murder late Thursday morning. An alleged accomplice is also under arrest.
The second suspect was not accused in the killings, but possessed the murder weapon used in the killings, authorities said. Gerald Williams, 27, was held on two weapons possession counts by prosecutors in Queens.
A Nassau County criminal complaint said Fuller used a .09-mm semiautomatic to kill his two victims, and Queens prosecutors said one of the weapons Williams is accused of possessing was a .09-mm handgun.
About 50 police officers, most in uniform, stood in the courtroom and about 50 more filled the hallways during Fuller's initial appearance on Long Island. He did not enter a plea on two counts of first- degree murder, robbery and weapons charges.
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