ALHAMBRA  (AP) — A Utah man was arrested Tuesday on suspicion of shooting an off-duty Los Angeles County sheriff’s deputy at a fast-food restaurant, and authorities say they are investigating whether he killed another man an hour earlier in attacks that both appear to be random.

Rhett Nelson, 30, of St. George, Utah, was taken into custody by Long Beach police Tuesday after he stopped at a church and called his father in Utah, sheriff’s Homicide Bureau Capt. Kent Wegener told reporters at a Tuesday afternoon news conference.

“In that call, he referred to committing a murder in Southern California,” Wegener said.

The father called police, who traced the call to the church, Wegener said. Soon afterward Long Beach officers saw Nelson in a car near the church and took him into custody without incident. They couldn’t immediately say if he had yet obtained an attorney.

He is suspected of walking into a Jack in the Box restaurant in the eastern Los Angeles suburb of Alhambra on Monday night and shooting Deputy Joseph Gilbert Solano in the head.

Solano, 50, was in grave condition and on life support, Sheriff Alex Villanueva told a Tuesday afternoon news conference.

“This is the part of this job that I don’t relish,” Villanueva said. “I always dreaded this would happen. It happened way too soon.”

Solano joined the Sheriff’s Department in 1999 after earning an Associate of Arts degree from Pasadena City College. He later left the department to work for a year for the Alhambra Fire Department before returning to the sheriff’s department in 2006. Most recently he was assigned to the department’s custody division.

Villanueva told reporters that Solano is a family man, well-liked by everyone who worked with him and is the sole support of his mother after his father recently died. He was off duty and running an errand for his mother when he was wounded Monday.

“He was taking his mother’s vehicle to be serviced at the Jiffy Lube, which is was right next door to the Jack in the Box,” Villanueva said.

He was waiting for his food order at the counter when his attacker walked up and shot him in the head, calmly walked out of the restaurant and drove away.

Solano wasn’t wearing anything that would identify him as a law enforcement officer, authorities said, adding the attack appeared to be random and the men didn’t know each other.

Surveillance video showed the attacker leaving the restaurant and later changing clothes. Wegener said the clothes and the gun later found in Nelson’s car appear to match those he had when Solano was shot.

After Nelson’s arrest police linked him to the fatal shooting of a 30-year-old man who was standing on a street near downtown Los Angeles just an hour before the Alhambra shooting.

“A vehicle arrived and according to other witnesses the individual inside that vehicle had a brief exchange with our victim, gunfire erupted and our victim sustained at least one gunshot wound and died at the scene,” LAPD Police Chief Michel Moore said.

Nelson’s description and the 2012 Kia he was diving matched those seen at both shootings, Moore told reporters.

Investigators were also at a loss to explain that attack, adding it appeared the victim and the shooter didn’t know each other. The 30-year-old man’s name was not immediately released.

Authorities said Nelson’s family in Utah had recently reported him missing and they are attempting to determine if he may have been involved in any other crimes since arriving in Southern California, apparently last week.