McDowell attended and played college football at Michigan State under head coach Mark Dantonio. In the 2014 season, McDowell played in all 13 games as a true freshman and had 15 tackles and 1.5 sacks. As a sophomore in 2015, he was named an All-American by Fox Sports. On November 29, 2016, McDowell was named Second Team All-Big Ten. On December 5, 2016, McDowell announced that he had signed with an agent and would enter the 2017 NFL Draft.
Professional career
McDowell received an invitation to the NFL Combine and completed every combine drill, except for the short shuttle and three-cone drill. He also participated at Michigan State's Pro Day, but chose to run only positional drills for scouts and team representatives in attendance. McDowell attended nine private workouts and visits with the Baltimore Ravens, Dallas Cowboys, Detroit Lions, Indianapolis Colts, Miami Dolphins, Minnesota Vikings, Philadelphia Eagles, Seattle Seahawks, and Washington Redskins. NFL draft experts and analysts projected McDowell to be a first round pick. He was ranked the top defensive tackle available in the draft by ESPN and NFL analyst Bucky Brooks, the second best defensive tackle by Sports Illustrated and Pro Football Focus, and was ranked the third best interior defensive lineman by NFL media analyst Mike Mayock. The Seattle Seahawks selected McDowell in the second round of the 2017 NFL Draft. On May 25, 2017, the Seahawks signed McDowell to a four-year, $6.95 million contract with $4.40 million guaranteed and a signing bonus of $3.19 million. A few weeks prior to training camp, McDowell was involved in an ATV accident and was placed on the reserve/did not report list on July 30, 2017. He later returned to practice and was placed on the non-football injury list on August 3 due to the injuries from the accident. He was arrested for driving under the influence of alcohol on September 22, 2017, and was sentenced to 12 months of probation on March 20, 2018. He was arrested again in December 2017 for disorderly conduct. On July 26, 2018, McDowell was waived by the Seahawks with a non-football injury designation, and subsequently placed on the reserve/non-football injury list the next day. On February 18, 2019, McDowell got into an altercation with police in Lathrup Village, Michigan, and was charged with assault, resisting arrest, and operating a vehicle while intoxicated. He was released by the Seahawks on March 2, 2019. In April 2019, he was arrested for receiving and concealing stolen property after police found a stolen car in his possession. The Seahawks filed a lawsuit against him in May 2019, after he failed to repay $799,238 of his signing bonus. McDowell was suspended for the first two weeks of the 2019 NFL season as a result of the February 2019 incident on July 12, 2019. He was reinstated from suspension on September 17, 2019. On October 23, 2019, he pleaded guilty to all of the criminal charges. He was sentenced to 11 months in prison on November 13, 2019.
