BRIGHAM CITY — Brigham City Police Chief Mike Nelsen said when his officers arrived on a call of a stabbing, Spencer Gerlach was very quiet and went right up to them.

"He just didn't have much to say at all. He just came out and kind of went to the officer, and he handcuffed him. There was little said at all," Nelsen said.

Moments earlier, police believe, Gerlach, 20, of Perry, stabbed his ex-wife, Keltsie Gerlach, 19, to death and then called 911 to report what had happened.

On Thursday, friends of the Gerlachs were still in shock and mourning over what happened.

"We're so sad for both families. They're both really good families," said neighbor Korina Lee. "It's a tragedy. It's sad when somebody dies. But it's just extra sad because it didn't need to happen. It's just awful."

The young couple's divorce was finalized just a month ago. Keltsie had only recently moved into her new apartment, 691 S. 600 East in Brigham City.

Nelsen said the Gerlachs had no history of domestic violence with his department. And as of Thursday, they had not found anyone who knew of any history of violence between the two.

As for a possible motive for the killing, Nelsen said, "The only motive would be just anger, that we have right now."

Whether the slaying was premeditated or the result of an argument that got out of control, Nelsen said Thursday he didn't know. There was also no immediate evidence of drugs or alcohol being involved.

The couple's 15-month-old daughter, Addie, was asleep in another room at the time of the attack, police say. The toddler was initially taken into protective custody by the Division of Child and Family Services. Keltsie Gerlach's mother took custody of the child late Wednesday, according to police.

Keltsie Gerlach's father, Sheldon Mansfield, who lives in Grace, Idaho, where his daughter grew up, called Keltsie a "fabulous mom."

"She didn't like contention, always avoided it. She would sometimes go along with things to avoid creating problems for others," he said. "She loved to get away and just spend time with family. She wanted to be involved in others' lives."

Val Gunther, who was Keltsie's LDS bishop, said he spent time with her family Wednesday night. He said the events of the past 24 hours have been "very difficult" on them.

Ryan Ahlstrom was a friend to both Spencer and Keltsie Gerlach and would go on double dates with them.

"A good family trying to figure things out. And earlier this year it kind of fell apart. But they were trying to progress and overcome some of the obstacles they had with the situation that they put themselves in. They're both good people. It's just sad that it happened," he said.

Keltsie Gerlach grew up in Idaho before moving to Utah, where she attended Box Elder High School, according to her Facebook page. She has many family members in both Grace and Brigham City and was the oldest of four children and four step-children.

Spencer Gerlach is originally from Provo and attended Utah State University, according to his Facebook page. He filed for divorce from Keltsie in February, according to court records.

According to the Gerlachs' divorce decree filed in 1st District Court, the couple was to have joint custody of their child with Keltsie being the primary custodian.

According to court documents, Spencer Gerlach had plans to move to the San Francisco area.

Keltsie Gerlach's family has set up a GoFundMe page to help raise money for her young daughter at www.gofundme.com/KeltsieAddie.

Contributing: Mike Anderson

Email: preavy@deseretnews.com, Twitter: DNewsCrimeTeam