"They know what she's been convicted of. I don't think either one of them grasps the finality of that or believes it," said Nelson in an interview with 9Wants to Know.
For the first time since his wife Shawna Nelson was convicted in the first-degree murder of her lover's wife, Heather Garraus, Ken Nelson is speaking publicly about their life together and his life since the murder.
"I never in a million years thought Shawna was capable of doing something like that," Ken said in the April interview.
Shawna Nelson had a four-year affair with another married man, former Greeley Police Officer Ignacio Garraus, and gave birth to his child.
On Jan. 23, 2007, Shawna drove to the bank where Heather Garraus worked, waited outside in the dark, and shot Garraus twice, ending her life.
Ken Nelson said that's the moment his children's childhoods ended too.
"They're not the same kids," he said. "They don't play the same way with 8 and 10 year olds. They know way too much for any 8 and 10-year-old and have been exposed way too much for any 8 and 10-year-old should be."
Ken is raising the two children he had with Shawna, an 8-year-old girl and a 9-year-old boy, along with the 2-year-old child she had from the affair with Ignacio Garraus.
When asked how he explains to the children why their mother will be spending the rest of her life in prison Ken said he tells them their mother has "made some bad choices that she's going to have to live with and unfortunately we're going to have to live with."
Shawna hasn't seen her three children since the day of the murder. Ken said he is trying to make arrangements for Shawna to see her children again in her new home, the Colorado Women's Prison in Canon City.
"She loved her kids more than anything else in the world," he said.
The murder put Shawna and Ken's marriage in the media spotlight. Both admitted to having affairs. Shawna had admitted to having affairs with men and women.
Their marriage was not always that strained. The two married in 1996 in a backyard ceremony at a friend's house. They are still married today, but Ken has filed for divorce and it should be final by the end of May.
Ken said the couple started having problems after his second child was born and Shawna went back to work.
He learned about her affair with Garraus by reading her diary left on the stove in the kitchen.
"It wasn't a real fun thing to read," Ken admitted.
Still, even as Ken sat in the squad room while on duty as a Weld County Sheriff's deputy the night of the murder and the call went out, he thought it was a joke.
"I couldn't believe it. I told everybody in the room if somebody's playing a joke, I don't think it's funny," he said.
Shawna shot Garraus the day before Ken's birthday.
Ken now believes his wife Shawna was trying to set him up.
"Why else would she be wearing my underwear, wearing my socks, my baseball cap, and drive my truck that she hated?" Ken asked rhetorically. "Is there any other explanation for that? I can't think of one."
Ken thinks Shawna almost got what she wanted.
"Heather would have been out of the way. I would have been out of the way," he said.
Because Ken Nelson stopped Shawna after the murder, but didn't detain her, he was charged with tampering with evidence and accessory to first-degree murder. The charges against him were dropped after her conviction. Nelson said he was told by the Larimer County District Attorney that testimony that came out in the trial proved his innocence.
After the murder, Ken resigned from the Weld County Sheriff's Office and moved out of state. He has since moved back and said it is for the stability for his children.
Even after the affairs, the lies and the murder Ken said he doesn't hate his wife.
He said he married Shawna because she was sweet. But now, "I think she is where she needs to be," he said.
