SACRAMENTO, Calif. – A 76-year-old man operating an unlicensed chiropractic clinic out of his Oak Park, Calif., garage is suspected of killing one of his patients with a neck manipulation, according to Sacramento, Calif., police.

Antonio Arellano whose only training was a massage class he took in the 1940s was booked into the Sacramento County jail early Friday on suspicion of murder, authorities said.

According to police, Jose Lopez, 64, and his wife went to Arellano’s home on Washington Avenue on Tuesday. Lopez went to see Arellano for help with pain in his extremities, police said.

During the treatment, Arellano adjusted the victim’s neck, seriously injuring the man, police said.

Lopez was unconscious as he was brought out of the home and placed in a car, said police Sgt. Matt Young.

Lopez was taken to University of California at Davis Medical Center and placed on life support. Two days later, he was declared brain dead.

Arellano, who was a teenager when he took the massage course, has been operating an unlicensed chiropractic business for years and “has a substantial following,” Young said.

According to police, he cultivated a practice by handing out business cards in his neighborhood.

“Obviously he is unlicensed and should not have been engaging in this type of business,” Young said.

The trip to see Arellano was Lopez’s first or second, according to police. Lopez’s wife had received treatment “a couple of times before,” Young said.

“If any good can come from this horrible ordeal, it’s that people need to utilize the technology available to verify someone’s credentials and license status, especially when seeking services of a medical nature,” Young said.

There are no records to indicate Arellano was a licensed chiropractor, according to the state Board of Chiropractic Examiners.

According to Dr. Kassie Donoghue, a Sacramento chiropractor, the process of becoming licensed in California is “rigorous.”

The process involves a 3½-year program in chiropractic college that includes science coursework. There are national and state board exams.

“It’s not something you can just fake,” Donoghue said.

She said if chiropractic techniques are not done correctly, “they can be very, very dangerous.”