The 28-year-old actor admitted charges of felony menacing and third-degree assault at a court hearing in Boulder County, Colorado on Thursday (08Apr10) relating to a fight with a friend in the state last year (09).
Bonsall also pleaded guilty to a charge of violating his probation in connection with a 2007 assault on his girlfriend after missing a 2008 court date.
The star was sentenced to two years probation for his part in the Colorado altercation, and was ordered to complete five days in the Boulder County Jail's work-release program and 40 hours of community service for his previous probation violation.
Bonsall's lawyer, Yasmin Forouzandeh, blamed the star's ongoing substance abuse and mental health problems for his bad behaviour and asked the court to enrol her client in a treatment program, according to Colorado news website DailyCamera.com.
A judge will decide next week (beg12Apr10) whether Bonsall is eligible for the region's "integrated treatment court".