According to Orlando-Orange County public records (case 48-2004-MM-012392-O), on Halloween 2004, while a student at UCF, Marshall was arrested in Orlando on charges of assault on a law enforcement officer, refusal to obey, disorderly conduct and resisting an officer.
On January 1, 2007, Marshall was present at "The Shelter," a nightclub in Denver, Colorado, along with teammates Javon Walker and Darrent Williams. The trio was attending a birthday party held for and by Denver Nuggets forward Kenyon Martin. As the players were leaving the club in a limousine, Williams was fatally shot in the neck after an unknown assailant opened fire on the vehicle. Willie Clark was later charged with the murder. Walker has stated in interviews that the shooter was likely a nightclub patron whose motive was retaliation after being involved in an altercation with Marshall's cousin earlier that night.
On March 26, 2007, Marshall was arrested in the Highlands Ranch suburb of Denver on suspicion of domestic violence after his girlfriend reported that following a domestic dispute, Marshall prevented a taxi she was in from leaving his house. Charges from the incident were later dismissed on May 25, 2007, after Marshall completed anger management counseling.
In the early morning of October 22, 2007, Marshall was arrested in the Denver-Aurora metropolitan area at the intersection of 14th and Blake St. for driving under the influence of alcohol. A trial was scheduled for September 16, but Marshall instead agreed to a plea bargain four days earlier; he pleaded guilty to a reduced charge of driving while ability impaired. He was sentenced to one-year probation and 24 hours of community service.
On June 12, 2008, Marshall was ticketed for an illegal lane change, then found to be without his license and proof of insurance. The case was eventually dropped as part of a plea bargain for the October 22, 2007 driving incident involving alcohol.
A September 17, 2008 article on CompleteColorado.com stated that the solicitor's office in Fulton County, Georgia filed misdemeanor battery charges on September 10 for an alleged incident on March 4, 2008, in Atlanta, Georgia. Marshall was booked on March 6, then released the next day after posting a $1,000 cash bond. The case was assigned to Judge John Mather in Georgia state court. On August 14, 2009, a jury in Atlanta found Marshall not guilty.
On March 1, 2009, Marshall was arrested in Atlanta for disorderly conduct after allegedly being involved in a fight with his fiancee, Michi Nogami-Campbell. Marshall was released on a $300 bond. The charges were dropped the following day.
On April 23, 2011, Marshall was stabbed near his stomach by his wife, Michi Nogami-Marshall. He was taken to a hospital and was released two days later. He has since made a full recovery.
It was later revealed by police that Marshall's wife did make a brief 911 call, but it only described an unspecified emergency and no mention of a stabbing ever took place. She is charged with aggravated battery with a deadly weapon and is free on $7,500 bail.
In a South Florida Sun-Sentinel article published on July 30, 2011, it was revealed that Marshall was diagnosed with borderline personality disorder at Boston's McLean Hospital after his incident with Nogami-Campbell. He is currently pursuing treatment for his mental illness and filming a documentary about his struggle.
On early Sunday, March 11, 2012, two days before his trade to the Bears, Marshall was accused of hitting a woman in the face at a New York club and being involved in a melee. The New York Post stated that Marshall, his wife and some friends were at Marquee when a brawl ensued, and Marshall punched the woman below her left eye, although he may have been attempting to hit the woman's friends. The investigation later ended after a lack of evidence of Marshall's role in the incident.