An elderly security guard who was left in critical condition after a man assaulted him in a Modesto parking garage on Friday has died, police said.

Modesto police said they found Karl Whitehead, 70, unconscious and with head injuries after responding to a 911 call regarding a man down in the parking garage at 900 block of 11th Street.

Don Lacey, 33, was arrested and booked into the Stanislaus County Jail for assault with great bodily injury. An enhancement was added to his charge for being a habitual offender, police said.

Police believe that Whitehead, who was working as a security guard in the parking garage, intervened in an argument between Lacey and a female parking attendant. Lacey struck Whitehead during the altercation, police said.

A witness followed Lacey from the parking garage until police arrived and took him into custody.