Accused murderer John Williams, 30, walked in minutes later.
Prosecutors say Williams shot Cole, a Somerset County Sheriff's Office corporal, while on duty on April 25, 2018 in retaliation for arresting his girlfriend days earlier.
Williams' lawyer says he was in withdrawals from heavy drug use and didn't mean to kill Cole.
“As he pointed the gun at Corporal Cole, he begged the defendant not to shoot him, saying 'No!' but Corporal Cole's pleas were disregarded by the defendant,” said Leane Zainea, Assistant Attorney General.
"In his intoxicated state, Mr. Williams immediate intention was to not go to jail,” said Verne Paradie, Williams' attorney. “So, while he intentionally pulled the trigger, you'll have to be convinced beyond a reasonable doubt that when he pulled that trigger, it was his intention or his knowing thought to kill Corporal Cole."
Zainea said the deputy slipped after finding Williams, who "got the jump on Cole" and used a 9 mm Ruger handgun at close range to shoot him in the neck. She said, the shot severed his spinal cord.
His defense attorney says Williams was a "different person" a year ago because of his drug use and "didn't think things through."
Paradie said Williams was like “an animal caught in a trap” who would chew off his own leg for drugs.