LOVELAND, Colo. -- A man arrested on suspicion of killing a process server who had handed him divorce papers was also strangling his two children when deputies burst into his home, authorities said Thursday.

Deputies were called to the home at about 8 p.m. Wednesday after the man's wife called 911 for help.

Upon arrival, deputies made a tactical entry into the home and found the bloody body of the process server. The suspect -- identified as 45-year-old James Whitler -- was lying on top of his children, with hands around their throats, authorities said. One of the children had also been stabbed.

"The father had the two children on the ground. There was a lot of blood at the scene. He was obviously choking both of the children," Larimer County Sheriff Jim Alderden said.

"When the suspect refused commands, Sgt. Gerry Baker tased the suspect once but with no effect. The second time he was tased, deputies were able to subdue him and place him under arrest," sheriff's spokeswoman Eloise Campanella said in a news release.

The 10-year-old boy and 12-year-old girl were unconscious. They were rushed to Medical Center of the Rockies where they were treated for their injuries and were listed in good condition.

Deputies said the suspect's wife, Lisa Whitler, sustained minor injuries but refused medical treatment. She had called 911 after the process server was attacked.

The sheriff's office said she and her husband were going through a messy separation.

"She notified him, I think it was probably around the 17th, that she was going to get a divorce," Alderden said.

So when the process server, 57-year-old Stephen Allen of Fort Collins, delivered divorce papers and a restraining order to Whitler, it shouldn't have been a surprise to Whitler, authorities said.

"Things appeared to be calm. Things went well," Alderden said. "He said he was going to get his suitcase and start packing -- actually had one of the children bring the suitcase to him."

"He went upstairs and packed and came downstairs with his stuff and his baseball bat," said neighbor Steve Rogers, who heard the story from Lisa Whitler after she ran outside to call for help.

Allen was beaten with a baseball bat and stabbed with a kitchen knife, the sheriff's office said. He died from multiple blunt force trauma and sharp force injuries, according to the Larimer County coroner.

“He was a big teddy bear,” said Jane Morris, Allen’s girlfriend.

Morris told 7NEWS reporter Lane Lyon the last time she spoke with him was around 3 p.m. Wednesday. Allen made no mention of serving Whitler, Morris said. She later found it odd Allen did not call her Wednesday night – the first time in their four and a half year relationship.

Morris learned of Allen’s death Thursday morning from a friend.

Despite a rough exterior, Morris said Allen was really “a caring, gentle man who loved the Lord.”

Allen is survived by a brother, three adult children, three grandchildren with one on the way, according Morris.

Allen was a Larimer County sheriff's deputy in 1984 and 1985 but he was not armed when he went to the couple's home as a private process server, the sheriff said.

The sheriff's office said Allen and Lisa Whitler even took the precaution of going through the home earlier in the day and removing a shotgun from the house.

Whitler was booked into the Larimer County Detention Center on suspicion of first-degree murder, two counts of criminal attempt to commit murder, and child abuse. He has no previous arrest record, according to the Colorado Bureau of Investigation.

Whitler was a campus monitor at Mountain View High School in Loveland until a few months ago. He was one of three paid unarmed security guards at the school, the newspaper reported.

Neighbors said they saw no evidence of violence at the home. James Whitler was president of the homeowner's association.

"They were just average, normal kind of folks, it seems," Rogers said.

Both children are students at New Vision Charter school, according to the Loveland Reporter Herald.

The attack occurred inside the home on Otero Avenue, northwest of Loveland. Investigators said the scene is so messy that blood spatter analysts will be at the home for several days collecting evidence.