SAN DIEGO - A 29-year-old man was jailed today on suspicion of attacking an employee at a North Park auto repair shop with a hammer, leaving the man in critical but stable condition.

Louis Richard Cedarholm was arrested in the 3800 block of Mississippi Street, near Jack's Muffler Service where the attack took place Sunday night, according to San Diego police. He was subsequently booked into jail on suspicion of attempted murder, assault with a deadly weapon and other charges, according to jail records.

The victim, Henry Rader, was allegedly hit with a hammer 13 times in an apparently unprovoked attack, for which a motive has yet been determined. He suffered numerous non-life-threatening injuries, including bleeding on the brain, skull and facial fractures, multiple lacerations, missing teeth and may lose an eye, according to police.

He was eating alone in the service bay around 8:10 p.m. Sunday, when his attacker approached, pulled out a hammer and struck the him in the head seven times, according to San Diego police.

After the victim fell to the floor, the suspect looked around the business office, but didn't take anything. He then headed back to the bay and proceeded to hit Rader in the head with the hammer six more times while he was on the ground, then left, police said.

A surveillance camera at the business on University Avenue near Mississippi Street recorded images of the suspect.

Rader's family is raising money via a GoFundMe.com page to help cover his medical expenses and the lengthy rehabilitation period in which he'll be unable to work. More than $9,500 has been donated since the account was activated Monday.