CHICAGO -- Investigators are trying to piece together what happened to NFL quarterback Jay Cutler's brother-in-law, who hasn't been heard from since his car was found abandoned more than a week ago near a remote dirt road in Utah.
Michael Cavallari, 30, lives in Southern California and was arrested on an allegation of making threats there Nov. 23, authorities said Monday.
Four days later, a rancher found Cavallari's car with its engine on and the air bag deployed in Utah, Grand County Sheriff Steven White said. It was about 200 miles south of Salt Lake City and 5 miles south of Interstate 70, in a part of the state that's home to several national parks.
Cavallari apparently was driving by himself, though it's unclear where he was going, authorities said. He is the brother of reality TV personality Kristin Cavallari, who married Cutler in 2013.
Evidence shows Michael Cavallari's 2014 Honda Civic hit a couple of big rocks and washes, likely causing the air bag to deploy, White said.
White said crews have been searching the area on foot and by helicopter but they have found no trace of Michael Cavallari. It's difficult to find footprints in the frozen ground, he added. Temperatures in the area have been at or below freezing every night since the car was found up against a small embankment.
There were no signs of foul play.
Hours before his Honda was discovered, Michael Cavallari - who lives in San Clemente, California - stopped at a convenience store about 60 miles away and asked for directions to Salt Lake City.
Credit card transactions and surveillance video show he was at the store in the town of Monticello at 3:30 a.m. on Nov. 27.
In California, Orange County Sheriff's Lt. Jeffrey Hallock said Monday that deputies arrested Michael Cavallari on suspicion of making criminal threats Nov. 23. He bailed out of jail Nov. 25.
He was arrested outside Dana Point City Hall with a loaded shotgun following a report from a woman who called the sheriff's department to say he had been outside her apartment with a shotgun, according to a police report.
The unnamed woman told deputies the two had argued days earlier, and she was afraid because he kept returning to her apartment. Police reported smelling alcohol on Michael Cavallari's breath when he was arrested. He acknowledged having a loaded shotgun in his trunk, the report said.
He was taken into custody without incident, and he denied doing anything to the woman, who reported the incidents to authorities.
Michael Cavallari works for his father's corporation, White said. He is single and has no kids.
Kristin Cavallari rose to fame in the mid-2000s when she appeared in the MTV reality series "Laguna Beach" and "The Hills." She and Cutler have three children together.
On Monday, Kristin Cavallari posted a photo on Instagram of her and her brother as kids at the beach with a message thanking people for their thoughts and prayers.
"We remain hopeful and I will share any news that we receive," she wrote.
Cutler starred collegiately at Vanderbilt and now plays for the Chicago Bears in the NFL. The 32-year-old said little Sunday when asked about whether the situation with his missing brother-in-law was a factor in his team's loss.
"No," Cutler said. "We stayed focused, and we adjust better than anybody."
Cutler's head coach, John Fox, said Monday he's aware of the situation but doesn't know much about it. Fox said the franchise provides resources for players to deal with off-field issues, including sports psychologists.
The Cavallari family asked authorities to respect their privacy in the first days after Michael Cavallari disappeared. They decided allow police to go public this weekend in hopes that somebody might come forward with more information, White said.
Michael Cavallari's father and stepfather have been in Utah to help with the search, the sheriff said.
Police are gearing up to launch new searches but are first strategizing the best areas to look. People recreate at sand dunes in the area, and White said he's hopeful someone who was there knows something.
Search continues for brother of Kristin Cavallari, brother-in-law of Jay Cutler