Former Missouri defensive end Aldon Smith has been suspended by the NFL for a full year, according to multiple sources.

Smith was arrested on Aug. 6 for a DUI, as well as hit-and-run and vandalism charges. It was his third DUI. The next day, the San Francisco 49ers released him. The Oakland Raiders signed him to an incentive-laden contract in early September. He has 21 tackles and 3.5 sacks this year.

Smith has had his share of off-the-field problems since joining the NFL in 2011. The arrest was the fifth of his five-year pro career. He had previous DUIs in 2012 and 2013. The second DUI came after he was involved in a one-car accident. He was also cited for weed possession following the accident, and voluntarily entered a rehabilitation facility.

In 2012, he was allegedly stabbed while trying to break up a fight during a party at his house. Two other people were shot during the incident. Smith was charged with three felony counts of illegal possession of an assault weapon, but the felonies were later reduced to misdemeanors.

Last year, Smith was detained and arrested after an incident at the Los Angeles International Airport where he allegedly became belligerent and uncooperative with a TSA agent. The TSA agent stated that Smith claimed he was carrying a bomb. Smith denied the accusation, and the charges were later dropped.

Last season, he received a nine-game suspension from the NFL for violating the league’s substance abuse and personal conduct policies.

The 49ers selected Smith with the seventh overall pick of the 2011 NFL Draft out of Missouri, where he’d been a Freshman All-American and had registered 17 sacks in two seasons. When he has stayed on the field and out of trouble, Smith has played well. He made the Pro Bowl in 2012. In his five-year NFL career, he has 170 tackles and 47.5 sacks.