Three years ago, Allen was expelled from Texas Tech and enrolled at East Mississippi Community College, where he starred on the popular Netflix series "Last Chance U." Allen now has proved to be the ultimate comeback story.
"All my emotions came out," he said Saturday after the Rams selected him. "Me and my family have been waiting on this moment for so long, and I'm just excited to be an L.A. Ram."
Rams general manager Les Snead said the call to Allen was among the best of the eight he made to players throughout the three-day draft.
"It's a really neat story," Snead said. "You could tell he was definitely appreciative to get this opportunity."
Allen said he has grown from his past mistakes. After a standout redshirt freshman season at Tech in 2015, Allen was arrested for second-degree felony burglary. Along with two of his teammates, Allen broke into a home and stole a gun safe containing seven handguns and long guns, and some electronics. He completed a 12-month pre-trial diversion program that led to the dismissal of charges after time in community supervision.
Allen spent a season at East Mississippi CC and then was given an opportunity to re-enroll at Texas Tech under coach Kliff Kingsbury, who is now coach of the Arizona Cardinals.
"I learned what's important to me, and that's definitely my family and that's definitely football," Allen said. "I don't want to do anything to jeopardize either one of those things."
Rams coach Sean McVay, who has watched "Last Chance U," said he respected how Allen owned his mistake and has moved forward with his life.
"I think that that gave him a perspective," McVay said. "When you hear how emotional and how important it was for him to get that call, specific to a lot of the things that he had overcome -- not only to get back to Texas Tech, but then to become a drafted player in the NFL -- I think there's an appreciation that he has, and you like how he responded from a mistake."
The Rams selected Allen primarily for his ability to contribute on special teams, but the 6-foot-1, 235-pound linebacker also is expected to add depth to a position group that includes Cory Littleton, Clay Matthews, Micah Kiser and Travin Howard.
In three seasons at Texas Tech, Allen had 17.5 tackles for a loss, two sacks and four interceptions. In his one season at East Mississippi CC, he led the team with 117 tackles.
As for his time on "Last Chance U," Allen called it a "weird" but "great" experience.
"People do recognize me from the show, they recognize me as sort of the good guy on the show," he said, chuckling. "The whole experience was just amazing, and I'm thankful for it because I was able to continue to play football."