Kent Whitaker's Life 10 Years After An Unspeakable Tragedy (VIDEO)

On December 10, 2003, the Whitaker family -- dad Kent, mom Tricia, and their sons Bart and Kevin -- arrived home after an evening celebrating Bart's upcoming college graduation. When they opened the door, Tricia and Kevin were immediately shot in their chests by a gunman inside the house. Kent ran toward the door and was shot in his shoulder. Bart ran in as well and was shot seconds later.

Tricia and Kevin both died that night. Kent and Bart survived the shooting. Just hours after the brutal attack, Kent vowed to forgive the person who killed his family members -- though he never expected his own son was behind it.

After a thorough investigation, authorities discovered that Bart had arranged the assassination. He was arrested, convicted of capital murder and sentenced to death.

Speaking to Lisa Ling from death row in 2008, Bart explained why he wanted to kill his entire family, weaving together reasons with envy, insecurity, anger and hate. Still, Kent kept his promise to forgive, even telling Oprah that forgiveness allows him to see past the tragedy to a life of excitement and possibility.

It's now been more than a decade since Kent's family was killed, and he tells "Oprah: Where Are They Now?" that nearly everything in his life has changed.

"For one thing, I got married," Kent says. "That's the best thing."

Kent met his wife Tanya through a mutual friend, who had mentioned to her that Kent had "a little story" that she didn't need to worry about at that early stage of the relationship. Tanya didn't think much of it until Kent revealed the entire story during their second email exchange.

"He was basically giving me a chance to run," Tanya says. "But I'll tell you what. Kent's honesty and integrity and his heart, it drew me in. I couldn't say 'no.' I just fell more and more in love with him."

Bart, meanwhile, still sits on death row. Kent and Tanya visit him once a week.

"My relationship with my son is much better than it had been. He has become much more open and honest with me about his failures, about his losses, about the things that were bothering him at that time," Kent says. "I just wish that I had had the relationship with him then that I do now."

Kent admits that there are still days when he struggles, especially with the fact that he has a loved one on death row.

"You know that there's always going to be a strong possibility that you'll receive a phone call saying that a date has been set and you now have less than maybe 200 hours before your son dies," Kent says. "If that's what happens, I'm going to be on the other side of the glass. He's going to know I'm there, and he's going to know Tanya's there."

Today, Kent and Tanya travel the country speaking about the power of forgiveness.

"Oprah: Where Are They Now?" airs Sundays at 9 p.m. ET on OWN.