A 75-year-old Carrollton man pleaded guilty Thursday to murdering a former Coppell schoolteacher. He was sentenced to 15 years in prison.

Leroy Tellgren was arrested in April, less than a week after the disappearance of 49-year-old Kathleen Garza, a friend and former colleague at Coppell Middle School East.

He was scheduled to stand trial in Denton County next month. Thursday's guilty plea was the result of an agreement between Tellgren and prosecutors to lead them to Garza's body.

"We wanted some kind of closure," Garza's husband, Raul, said of the decision to make the plea bargain. "We wanted to find Kathy, wanted to give her a proper burial."

Given Tellgren's age, the 15-year sentence is tantamount to life in prison, prosecutors said.

"We hope he doesn't make it to 15 years," Raul Garza said. "We understand that prison life is hard on age, and we're hoping it's as hard as it can be with him."

Tellgren will be eligible to be considered for parole in 7 ½ years, said Jamie Beck, first assistant district attorney and spokeswoman for the Denton County district attorney's office.

On Thursday, Garza addressed Tellgren in open court.

"What kind of man are you?" Garza said to Tellgren. "You're not a man – but a shell of human being not worthy of love, because you are incapable of showing that to others.

"You let evil rip out your spine and your guts."

Afterward, Garza said he felt a release in addressing his wife's killer.

"I felt like a big burden was lifted off me," he said. "I got to look him in the eye. It felt good telling him what kind of animal he is. I know it's not going to bring Kathy back, but it was a release of anger and frustration that was good to get off my chest."

Kathleen Garza was last seen alive on a surveillance video from a Coppell coffee shop. The video showed her and Tellgren leaving the shop and heading to his pickup.

When investigators confronted Tellgren after the woman's disappearance, they found blood on his shirt and her jewelry in his pocket.

For months, Tellgren refused to cooperate with investigators, police said.

Then, earlier this month, searchers found the former teacher's remains in a wooded area near Lake Lewisville. She had been shot in the back of the head with a .32-caliber handgun, lead prosecutor Rick Jackson said.

The Garza family is planning a private burial.

"Kathleen's death was a tremendous blow to all of us," Garza said tearfully during the hearing. "Yet, I know she is at peace and she wants us to be strong. ... And nothing will take her love away from us."

The Fort Worth Star-Telegram contributed to this report.