Johnson was cited for speeding and eluding arrest on Saturday for allegedly driving his motorcycle 60 mph in a 25 mph zone and failing to pull over immediately for police. Just two days earlier, Johnson was ticketed for maintaining a disorderly house after neighbors called police about a loud party at his residence.
"I am disappointed that things didn't work out better for De'Andre," Iowa coach Kirk Ferentz said in a statement. "We wish him all the best moving forward."
Johnson played in four games in 2011, rushing 18 times for 79 yards.
His dismissal is the latest in a string of problems at running back for the Hawkeyes. Leading rusher Marcus Coker transferred to Stony Brook in the offseason after some off-the-field problems. Backup Mika'il McCall also left the team after earning an in-season suspension. Jordan Canzeri tore his ACL this spring, and incoming freshman Greg Garmon was convicted of drug paraphernalia charges last month.