He was accused of forcing his way into an apartment in Columbia, Missouri, and pushing a woman down the stairs, but no arrests were made in the case and he wasn't charged. He was also arrested when marijuana was found in a car he was in, although he was never charged in that case, either.
He was also arrested another time for marijuana possession, but that charge was dropped.
"All the decisions I made, I wish I could take it back," Green-Beckham said. "It's happened. I was young. I made mistakes. I understand that and I just want to focus on one thing and look forward to this draft and focus on being the best I can be."
Green-Beckham said he had wanted to stay at Missouri and still wishes he could have finished there. He wouldn't go into detail about his "mistakes," and when he was asked specifically about the allegations of pushing a woman down the stairs, he said he plans to show teams how he has grown.
"I proved that I'm a better person by showing them how mature I've grown," Green-Beckham said. "This past few months have been real tough on me, missing a whole season, missing playing with my teammates, just missing football, period.
"Just looking from the outside in, seeing things that I've never seen before, I just want to take advantage of that and make sure I'm going to be here for all my teammates and make sure that I'm still going to be the best guy I'm going to be off the field and try to show everybody I'm capable of doing those things."
Green-Beckham, who measured in at 6-foot-5 and 237 pounds, said he believes his prior issues will hurt his draft stock. ESPN's scouting service has him rated as the seventh-best receiver in the draft.
When asked how he thinks he can get NFL teams to trust him, he said he matured after transferring to Oklahoma after his dismissal from Missouri in April 2014.
Green-Beckham said he was hopeful the NCAA would have let him played at Oklahoma last season, but it "just didn't fall into the right hands."
At Missouri, he had 87 catches for 1,278 yards and 17 touchdowns. The NCAA denied his waiver asking to play immediately for the Sooners, forcing him to sit out the 2014 season.