The Dodge County District Attorney filed charges of assisted suicide Wednesday against the former cellmate of Adam Peterson.

Peterson, 20, was charged with first-degree intentional homicide after killing Madison resident, Joel Marino, 31, in December 2008.

Two weeks before his scheduled sentencing, Peterson was found dead in his cell in the Dodge Correctional Institution Jan. 11, hanging from a bedsheet on the upper bunk of his prison cell. Dodge County District Attorney William Bedker filed criminal charges alleging Peterson’s cellmate, Joshua Walters, 20, assisted with the suicide.

Walters was asleep in his bottom bunk that evening when he woke up to use the bathroom and saw Peterson. He said Peterson was “looking at me all weird” and his face was “right there looking at me,” according to the complaint.

When Peterson remained silent, Walters said he got up and turned on the light to realize Peterson was hanging from the bedpost. Walters then called out the cell door to alert the correctional officer Peterson was unmoving, according to the complaint.

Walters said in the complaint he had no reason to want to hurt Peterson and had not done anything to harm him. He also denied he put a towel around Peterson’s head or neck or aided in his suicide.

Authorities of the Dane County Jail had Peterson on suicide watch after he unsuccessfully attempted suicide Sept. 25, but he did not remain on suicide watch when he arrived at DCI Dec. 8.

“Based on [Peterson’s] screening and assessment at intake at the prison, based on the information we had prior to his arrival and based on security level, [Peterson] underwent close monitoring by our staff during his time in the assessment and evaluation unit,” Public Information Director John Dipko said. “He also received follow-up attention that was commensurate with his needs while in the unit.”

On Jan. 13, another inmate, identified as JGQ, came forward with information concerning Peterson’s death.

In the complaint, JGQ said Walters told him he has it “all planned out” and convinced Peterson to commit suicide that week, telling Peterson he would even commit suicide shortly after. JCQ said Walters also suggested Peterson should write a suicide note and place it in the waistband of Peterson’s pants.

According to the complaint, JGQ said Walter told him he tied a noose to the top bunk for Peterson and checked its supportability by putting his own head through the noose.

Walters then told Peterson to put his head through the noose and twist the bed sheet until he could not breathe. Walters continued to help Peterson in his suicide attempt by putting a towel around Peterson’s neck to help him pass out, the complaint said.

Walters only pretended to be asleep and then woke up to find Peterson hanging, the complaint said.

“The safety and security of inmates under our custody is a top priority at the Department of Corrections,” warden Timothy Lundquist said.