A South Floral Park man who is already serving a 100-year federal sentence for a series of armed robberies was convicted of murder and weapons charges by a Queens Supreme Court jury, which found he killed his girlfriend’s ex-boyfriend in a Jamaica motel six years ago.

Max Cagan, 52, formerly of Kingston Avenue, is scheduled to be sentenced on Nov. 22 in the June 2010 murder of Edwin Vega Quinones, who was shot in the face after, prosecutors said, he was lured to the Par Central Motor Inn on Parsons Boulevard to avenge an assault Quinones allegedly committed on Quinones’ ex-girlfriend, Arlene Molina.

“This act of violence clearly demonstrates that the defendant is a danger to society and warrants a lengthy prison sentence in order to protect all law-abiding people,” said Queens District Attorney Richard A. Brown, in a news release Monday, after a three-week trial before Queens Supreme Court Justice Gregory L. Lasak.

Cagan’s attorney, Anthony Battisti of Glendale, could not be reached for comment.

Prosecutors and Cagan’s former attorney, Thomas Ambrosio of Lyndhurst New Jersey, said Cagan is already serving 172 years in federal prison for seven violent robberies of convenience stores and gas stations in New Jersey with a partner, Nelson Otero of Fort Lee, New Jersey, between March and May 2010.

Otero was also convicted and received a similar sentence, authorities said.

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Some victims were pistol-whipped and, in one of the heists, a Wayne, New Jersey police officer was shot in the head.

Cagan’s sentence on the second-degree murder and seconddegree criminal possession of a weapon charges will be served concurrently. He faces up to 25 years to life on those charges.

The fatal shooting happened on June 5, 2010, when Molina met with Quinones in the hotel room and allowed Cagan in, at which time Cagan shot Quinones with a 9mm handgun, officials said. The couple fled to New Jersey, where they were caught.

Molina, who pleaded guilty to manslaughter in connection with the case on May 4, 2011, is already serving a 20-year sentence.