Witnesses told police that the man, who’s been identified as Michael Paul Adams, 27, walked up behind the teen, grabbed him and stabbed him in the neck, according to a probable cause statement obtained by CNN affiliate KPHO/KTVK.

Family members said the teen, Elijah Al-Amin, had gotten off of work about 11:30 p.m. on Wednesday and had spent some time with his girlfriend before stopping at the store.

Police said a witness was trying to help Al-Amin by applying pressure to his neck when they arrived at 1:42 a.m. Police and fire personnel provided medical care and he was taken to the hospital, where he was pronounced dead at 2:05 a.m.

The witnesses told police that Al-Amin hadn’t done or said anything to provoke the attack. One said Adams didn’t say anything to the teen before stabbing him.