FRANKLIN CO., Ohio (WCMH) – A Grove City man will spend at least the next two decades in prison after pleading guilty to murdering his ex-wife.

The case against Jeremy Roberts, 43, was set to go to trial, according to Franklin County Prosecutor Ron O’Brien. On Monday, Roberts entered a guilty plea, more than four years after he was charged with aggravated murder. He was sentenced to life in prison without the possibility of parole for 25 years.

O’Brien said Roberts will likely be given credit for time served, since he’s spent the last four years in jail or in custody for mental health and competency exams.

The case began on June 10, 2012, when prosecutors say Jeremy Roberts’ ex-wife, Candice Roberts, came to pick up two of her three children from his Grove City apartment. Roberts was later charged with her death, accused of stabbing her repeatedly with a large kitchen knife.

Then, O’Brien said, he “handed a phone to the 13-year-old son and asked him to call the police.”

Roberts eventually got on the line himself, admitting to the 911 dispatcher what he’d done and to detectives when they arrived.

Speaking to NBC4 after her mother’s death, 16-year-old Kayla Roberts described the tragedy as losing her best friend.

“We did everything together,” Kayla Roberts said. “And now you just feel incomplete and abandoned and it’s just like half your heart fell out.”

O’Brien said the case was delayed for so long due to questions about Roberts’ competency to stand trial and his mental health, as well as continuances. He said Monday they were satisfied with the sentence.

“But it’s very difficult with two youngsters, who were present when their mother was murdered, to try and go forward and put that out of their mind,” O’Brien said.

In the years since this crime, O’Brien said, prosecutors and other county agencies have been working to streamline the process of obtaining protection orders to help domestic violence victims who are in ongoing abuse situations or disputes. He also noted that domestic violence is a felony for repeat offenses.

“This doesn’t look like this was an ongoing thing with the people involved in this instance, but I think it will help in others,” O’Brien said.

NBC4 reached out to the Roberts family to talk about the plea, but as of Monday afternoon, no one has responded.