UPDATE: Suspect and Victim Identified in Clayton Valley Shopping Center Stabbing

Joshua Cardone, a 19-year-old Concord resident, has been arrested in connection with the stabbing outside the Burger King in the Clayton Valley Shopping Center on Sunday afternoon, according to the Concord Police Department.

Cardone is being held at the Martinez Detention Facility on $1 million bail.

The victim, 20-year-old Concord resident Richard Gilliam, was stabbed at least once in the chest and died at .

Authorities say the two men were in some kind of a dispute before the stabbing, which took place about 4:20 p.m. Concord police say they are investigating what prompted the assault as well as the relationship between the two men.

Monica Kelly, who works nearby, said she witnessed the killing.

She was on a break when she saw a couple dozen young people gathered and heard them saying things like, "We need to teach him a lesson" and "We need to show him who's boss."

Kelly said she then saw the man on the ground and a woman trying to stop the bleeding.

Patch will update this story when further details are available.