BOUNTIFUL — Police arrested a Bountiful man on Sunday after he allegedly plotted to kill several people with firearms and explosives and tried to enlist a co-conspirator, according to charging documents.

Robert Jack Turville, 62, allegedly tried to engage a co-worker at a Midvale sporting goods store to help him kill five people, including with explosives planted in vehicle headrests, a Unified Police Department probable cause statement said.

Unified Police detective Ken Hansen said Monday the co-worker secretly recorded the alleged threats and criminal solicitation. That employee contacted police on Friday, Hansen said.

“With the nature of the threats being so specific, it required a lot of urgency,” Hansen said of the investigation. “We’ve had four detectives on this since Friday, just to make sure, because there was a big concern for the potential victims.”

“I’m 100% committed to taking a life,” Turville allegedly said on the recording, according to Unified Police.

Turville allegedly threatened to kill five people specifically, including his estranged wife and a church ecclesiastical leader, according to the probable cause statement.

He allegedly enlisted the co-worker in a plot to place an explosive called Tannerite in vehicle headrests of the people targeted. According to the U.S. Bureau of Alcohol, Firearms and Explosives, Tannerite is a compounded explosive commonly used in rifle shooting range targets.

Turville also allegedly said he owned or had access to 10 firearms, the arrest affidavit said.

“We know there was a plan in place and that parts of that plan had been acted on,” Hansen said. “I’m not sure how much had been enacted, but we are happy we were able to intercede.”

The detective said the co-worker contacted police “pretty quick” after recording the conversation about the alleged plot.

“Once the person saw where this was going and how there were specific targets, that person decided to record,” Hansen said.

The arrest affidavit said police contacted Turville and he agreed to meet with an officer, but then he did not answer his phone.

Unified Police on Sunday set up a stakeout for Turville at his home on Ridgewood Way, but he was able to slip away, the police probable cause statement said. Officers later found Turville at a relative’s home in Holladay and arrested him.

He was booked into the Salt Lake County Jail on suspicion of possession or use of a weapon of mass destruction and criminal solicitation, both first-degree felonies; three counts of threat of violence, one a second-degree felony and two class B misdemeanors; and one count of class A misdemeanor possession of a deadly weapon with intention to assault.

Police asked that Turville be held without bail. They said the man had his U.S. passport when he was arrested.

Hansen said Turville was fired from the store after managers learned of the alleged threats.

He also said Unified Police’s mental health unit led the investigation. He said the unit is used when an alleged suspect is in crisis or is displaying potential mental health problems.

The Davis County Sheriff’s Office provided tactical support for the stakeout in Bountiful, spokeswoman Liz Sollis said.

Formal charges against Turville had not been filed as of late Monday morning.