A Kansas prison inmate who was just 17-years-old when he stabbed a social worker to death back in August ot 2004 has died in prison.

According to the Kansas Department of Corrections, 39-year-old Andrew Ellmaker died Tuesday at the El Dorado Correctional Facility.

Ellmaker was found unresponsive in his cell. Staff and Emergency Medical Service personnel administered life-saving measures but were unable to revive him. The cause of death is pending the results of an independent autopsy.

Per protocol, when a resident dies in the custody of the Kansas Department of Corrections, the death is under investigation by the KDOC and the Kansas Bureau of Investigation. The investigation is ongoing.

Ellmaker was serving a life sentence for convictions of first degree murder and aggravated battery in Johnson County.

According to court records, Ellmaker’s convictions arise from the murder of his social worker, Teri Zenner, and the aggravated battery of his mother, Mary Susan Ellmaker ). When the crimes occurred in August 2004, Ellmaker was 17-years-old and a senior in high school. He had a long history of mental “dysfunction,” dating back to his early childhood. Ellmaker had been diagnosed with having schizotypal personality. As part of his treatment regimen, Ellmaker was assigned a social worker through the Johnson County Mental Health Center, and Zenner had served in that role for about a year. 

On the day of the crime, Zenner came to Ellmaker’s home for an after-school visit. Initially, Ellmaker and Zenner were the only ones in the home.

According to Ellmaker, when Zenner arrived she indicated the meeting would be short. She quickly completed some paper work for Ellmaker to sign and then prepared to leave. But Ellmaker did not want her to leave, and he asked her to go upstairs to his bedroom.

Eventually Ellmaker “convinced” Zenner to go to his bedroom. Once there, Ellmaker pulled out his sharpest knife, which he described as a sharpened chef’s knife. Zenner told him she was scared, needed air, and wanted to leave. She told Ellmaker that she would not report the incident, but he told the detective, “I knew she was going to go to the police about me holding her at knife point in my room so I did it.”

According to Ellmaker, he “did it” when his mother Sue came home earlier than he expected. He explained that Zenner was crying loudly when he heard his mother come into the house. Sue yelled for her son to come downstairs. When nothing happened, Sue persisted, telling Ellmaker numerous times that she wanted both of them to come down. At one point, Sue threatened to call the police, and Ellmaker replied, “When?” Giving Ellmaker until the count of three to come downstairs, Sue began counting down, “Three, two, one.”

When Sue got to “one,” Zenner sprang for the door. As she did, Ellmaker stabbed her in the throat.  Despite the wound, Zenner escaped; she came running out of the bedroom and down the stairs. Ellmaker followed and continued stabbing her.

When Ellmaker and Zenner got to the bottom of the stairs, Sue placed herself between Zenner and Ellmaker, yelling for Ellmaker to stop. All three tumbled to the floor, and Sue rolled onto Zenner to protect her. Ellmaker stabbed Sue four times in the back, once in the chest, and once in the right arm; he also slashed her ear. Ellmaker stopped stabbing at them when the knife bent.

At that point, Sue ran next door to get help and call 911. Meanwhile, Ellmaker returned to his bedroom, turned on some music, and grabbed his chainsaw from the closet. He explained to the detective that he followed the instructions printed on the chainsaw’s box that detailed seven steps for starting and operating the chainsaw. Ellmaker then used the chainsaw to almost sever Zenner’s left forearm and her neck. He also slashed her head, back, and right hip. At this point, the chain broke.

After using the chainsaw, Ellmaker tried to commit suicide by ingesting a variety of pills. He then left the house with two pellet guns and tried to leave in Zenner’s vehicle. When he had trouble getting the car to start, he took gasoline from the garage, poured it on the vehicle, and set it on fire. Ellmaker ran into the street as police arrived. The police ordered him to drop his weapons, which he did.