A dirty ex-cop who’s accused of killing his girlfriend and shooting her pal tried to cut a plea deal to halve the time he was facing — setting off a flurry of protests.

Former NYPD Officer Jerry Bowens of Brooklyn offered to plead guilty to fatally shooting girlfriend Catherine D’Onofrio in 2009 and accept the full sentence of 25 years to life to avoid a consecutive stretch for the attempted murder of her friend, Melissa Simmons.

But D’Onofrio’s mother and sister — as well as Simmons — fired off emotional letters imploring the judge to reject Bowens’ bid, it was revealed yesterday in court.

“The only sense of safety I get is knowing that he is locked away in prison,” Simmons wrote.

D’Onofrio’s mother, Jane, begged Brooklyn Supreme Court Justice Matthew D’Emic not to accept a plea for less than 50 years to life.

Bowens, a former narcotics cop, had initially been busted for stealing drugs from suspects and then passing them to informants — when he allegedly went berserk and attacked the women.

The ex-cop — who was convicted on the drug rap — said after the attack, “Catherine stated she had [another] boyfriend . . . She laughed at me, which made me really mad.”