Mark Humphrey/Associated Press
Guillard was married at the time, but he reportedly attacked his mistress after she asked him about leaving his wife.
According to the police report, “she was scared he ‘might kill her'” after he allegedly choked her, causing injuries to her face and neck.
The police arrested him for second-degree assault and strangulation.
This news comes on the heels of Guillard’s more recent arrest for his involvement in a bar fight earlier this month. Per TMZ Sports, he was captured on video punching other people in the bar, including one woman.
There was a warrant out for his arrest and he was eventually taken into custody when he appeared in court on Sept. 10 for his domestic assault case.
The 35-year-old competed in the UFC from 2005-14 but has continued to appear in mixed martial arts competitions, including Bellator and most recently the Rizin Fighting Federation in Japan. His last match was a July loss to Takanori Gomi.