During the 1980s and early ‘90s, the middle linebacker was relentless on the football field, but his on-field glory was overshadowed by a disastrous decision.
The Crockett, Texas native had the intimidating nickname Mean Gene the Hitting Machine, but the hardest hit he ever gave is the one he gave himself.
"Something went into my stomach and it's like a hurt came up over me and I was just weak," said Eugene. "Fifty-four months? I'm trying to do the math in my head and confusion all comes in my head. Four years?"
The federal government said he was part of a $20 million mortgage fraud scheme. He and nine others were implicated.
Eugene thought he'd get probation with his guilty plea and avoid a trial and lengthy sentence.
"They take me to Seagoville, and then when I get there, I have to undress and I'm looking for a coat hanger and they say ‘Nah, nah, nah, you don't have to worry about hanging that up. Throw it on the floor; we get it,'" said Eugene. "And then they give you this orange suit."
That's when reality hit. He was put in the hole for protection because he'd been a Dallas Cowboy.
Alone for three days, he said God showed him some things.
"The people that I had hurt and all the things I felt I was getting away, with he showed it to me," said Eugene. "Detail by detail, person, whatever I've done, he showed it to me, and that's when that hurt, hurt so much. To the point I was in a fetal position and God was just pouring it on me, pouring it on me and I couldn't do nothin' but cry. I cried because I hurt people. I've done wrong and I wasn't raised like that… at that time, it sounded like a great opportunity for me to still be able to live the lifestyle that I was accustomed to while playing football."
"What impact did it have on your wife and sons?" FOX 4's Clarice Tinsley asked.
"It was probably the toughest thing we'd been through as a family," said Eugene. "The kids had to go to school, the wife had to go to work…and for them to handle it the way they did with class and with the support and with the love that they showed…she's the rock."
While Sharon Lockhart didn't want to take the focus, she told FOX 4 "Eugene is strong, hardworking and loves his family. He's made bad decisions but we all do. He's gonna be OK. We'll be OK."
Their three sons had to grow up fast while their dad was in prison, but things are different now.
"Family life is family life, you know," said their son, Bryan. "It's great. I mean my dad's home. I'm just trying to get him back up on technology, you know, smart phone, Twitter, Instagram all that stuff."
Eugene, 54, is the grandfather of 19-month-old Bryson, who calls him Poppi.
Eugene loves to cook, and his smoker and barbecue pit are where he likes to hang out now.
"And that's what you have to be real careful about: wanting more, more, more, and I think one of the most important things is to be able to use that talent God has given you to help the need of others," said Eugene.
"Would you be here if you hadn't gone to prison?" asked Tinsley.
"I think that besides my relationship with Jesus Christ, my relationship with my wife , my family, going to prison was perhaps one of the best things that ever happened to me because I got that chance to find out exactly who I was, what my purpose in life is," he said. "My purpose is to serve."
Eugene served time in the Florence federal prison camp in Florence, Colorado. He'd studied at seminary before his legal problems got worse.
"Did you minister to inmates in Colorado?" asked Tinsley.
"Absolutely," said Eugene. "For 19 months…there was 99 men who accepted Jesus as their Lord and savior. I didn't save them ‘cause I can't save. I delivered the message."
He has boxes of his Colorado prison camp sermons and reads them daily and starts each day reading the Bible.
"Because you were a Dallas Cowboy, did you have threats from other inmates who wanted to make a reputation off of you?" said Tinsley.
"The main thing is that I hadn't always been saved, so if that hitting machine part of me needed to be brought back up, I was willing to do it because I was intending to come back home," said Eugene.
Lockhart's "mancave" is Cowboy heaven , including a seat from Texas Stadium signed by teammates, a signed Ron Springs jersey and a signed jersey from Randy White, the teammate who spoke up for him in federal court.
"I've been broken, but God has put me back together again," said Eugene. "I have a purpose to live and I'm gonna live within my purpose."
Eugene was incarcerated for three years. He faces two years of probation.
Tinsley asked how he plans to avoid trouble. He says he's had counseling and sessions with a life coach.
He says faith and doing the right thing are his armor.
He hopes to write a book and become a motivational speaker for students, adults and prison inmates.
He also hopes to be able to join alumni Dallas Cowboys and greet his fans at AT&T Stadium.