The woman said he hit her, held her against the wall by her neck and threatened to kill her and her child, deputies wrote. She said Nielsen then grabbed her legs out from under her, causing her to fall to the floor and hit her head, deputies wrote.
A bailiff said he heard noises from the room and went in to separate the two. Nielsen said he caused the noise by kicking a chair, deputies wrote.
The woman said "she had suffered through many incidents of violence with Matthew" and she feared for her safety, deputies wrote. She said Nielsen had forbidden her to tell police the meth pipes were his and told her "to never call the police because Matthew needs no more trouble out of her," deputies wrote.
When officers tried to stop Nielsen's truck as he left the courthouse, he was speeding, police wrote. Some loose prescription pills, bottles of legally prescribed pills and a meth pipe were found in the truck, police wrote.
Nielsen was charged with third-degree felony possession of a controlled substance and possession of drug paraphernalia based on the woman's account of the Oct. 8 traffic stop. He was charged with third-degree felony witness tampering and misdemeanor assault in the allegations at the courthouse.
He was charged with third-degree felony possession of a controlled substance in connection to the drugs, along with driving with measurable controlled substance, reckless driving, possession of drug paraphernalia and two counts of possession of a controlled substance, all misdemeanors.
These are not Nielsen's first charges since he left the Salt Lake County District Attorney's Office in 2007. He is awaiting trial in three 2012 cases, one alleging domestic violence and child abuse, one alleging prescription drug violations and one alleging assault, criminal mischief, failure to stop at the command of law enforcement and damage to a communication device. In 2009, he pleaded no contest to falsifying a prescription of a controlled substance and completed drug court in Tooele County.
In 2005, while he was working in the prosecutor's office, he was disciplined in a Cottonwood Heights domestic dispute during which he allegedly threatened a sheriff's sergeant with political retaliation.
Nielsen's attorney could not be reached for comment.