Keri Houston, 18, was getting out of her car, parked outside her home near 200 East and 700 South, when police say Arrats crashed into her about 5 p.m. The impact nearly took off her leg below the knee, according to police.
Neighbors and other people assisted the woman and controlled the bleeding from her leg by using a tourniquet.
On Wednesday, she was listed in critical condition at Intermountain Medical Center in Murray. No update was available Friday.
After hitting Houston, Arrats reportedly kept driving for several hundred feet until he crashed through a fence and into a yard.
"When he got out, he was screaming 'What, what, what did I do?' " according to Roosevelt police Detective Pete Butcher.
Arrats allegedly packed up his belongings and was ready to take off, but police arrested him at the scene. Investigators suspect Arrats had a controlled substance in his system and that he was texting at the time of the crash. Butcher declined to specify what type of drug they suspect Arrats had used.
There were multiple texts sent within the minute leading up to the crash, one of which was Arrats' wife texting him "haha," Butcher said.
Arrats has a criminal history dating to 2004. He has been convicted twice on weapons-related charges, as well as aggravated assault, threat of violence, criminal mischief, unlawful detention, intoxication and possession of alcohol by a minor, court records show.