A grand jury in Essex County, N.J., has declined to bring criminal charges against a police officer who fatally shot an unarmed banking executive from Atlanta last July during a confrontation in a park.

The banker, Defarra Gaymon, 48, had been in the state for an alumni reunion for his class at Montclair High School. The officer, Edward Esposito, 30, now a nine-year veteran of the Essex County Sheriff’s Office, was patrolling under cover in Branch Brook Park in Newark.

Around 6 p.m. on July 16, after chasing down a man and arresting him, Officer Esposito realized he had dropped his handcuffs in the woods and went to retrieve them, the Essex County Prosecutor’s Office said. The account of what followed came solely from Officer Esposito.

“We made an effort to find out if there was anyone who saw the events in the park,” said Katherine Carter, a spokeswoman for the prosecutor’s office. “No witnesses ever came forward to say they saw all, or a portion, of the encounter.”