Mesa police said a man was killed Friday after a driver struck him with his vehicle, returned to run him over and then stomped on his head multiple times before being stopped by a witness.

Police arrested the suspect in east Mesa following the death 63-year-old Christopher Heimer, who was pronounced dead at the scene.

Just after 12:30 p.m. Friday, Aug. 12, Mesa officers responded to the area of 6400 E. Alder regarding multiple reports of someone intentionally using their vehicle to run over another person, authorities said.

A witness used their own firearm and shot a round into the ground, preventing the suspect from leaving the area and allowing officers to take him into custody when they arrived, police said.

After speaking with witnesses and reviewing video surveillance cameras, officers learned Heimer was walking westbound on Alder at the same time the suspect was driving eastbound on the street.

The suspect swerved out of the roadway and struck Heimer as he was walking on the north sidewalk, throwing him into the landscaping of a fourplex apartment complex, police reported.

The suspect “continued to travel eastbound on the sidewalk, damaging mailboxes and landscaping before turning around and driving back toward Heimer,” police said.

Witnesses said the suspect drove onto the sidewalk, into the landscaping and ran over Heimer, who was already lying injured on the ground.

The suspect “then got out of his vehicle and proceeded to stomp on Heimer’s head multiple times.”

That is when, police said, one witness used their firearm to put an end to the suspect’s actions.

Witnesses also told officers the suspect was parked in a vacant lot, just northwest of Heimer’s residence, and that the suspect “honked his horn repeatedly, until Heimer came out of his home,” according to police.

 Police said they found where the suspect accelerated through the empty lot onto the street and saw skid marks from the suspect’s vehicle in the roadway and on the sidewalk where the incident occurred.

 John Lagana was booked into jail and charged with first-degree murder, police said.