A former Dane County (Wis.) sheriff’s deputy who shot and killed his wife and her sister last year is asking to be released from the mental institution where he’s committed.

Andrew Steele, 41, had pleaded guilty to two counts of intentional homicide for the Aug. 22, 2014, shooting deaths of his 39-year-old wife, Ashlee Steele, and her sister, 38-year-old Kacee Tollefsbol of Lake Elmo, Minn.

But a jury found Steele, who has the degenerative disease ALS, was not legally responsible for their deaths due to a mental disease or defect. He was committed to state mental hospital, but under Wisconsin law he can petition for release every six months.

Steele filed that first petition for release this week, the Wisconsin State Journal reported.

When Steele was diagnosed with ALS in June 2014, he was told he likely had two to five years to live.

One of his attorneys, Jessa Nicholson, said Steele’s health “has declined steadily but at a fast pace,” adding that he is using a wheelchair, has limited use of his hands and fingers and needs help breathing when he sleeps.

She said she’s concerned that when he needs a ventilator, the facility where he is housed won’t be able to meet his medical needs.

District Attorney Ismael Ozanne did not respond to messages left by the newspaper seeking comment about the release petition. His office was closed Thursday and a voicemail could not be left by the Associated Press.

Under state law, Circuit Judge Nicholas McNamara has 20 days to appoint a doctor to examine Steele. The doctor then will have 30 days to examine Steele and submit a report. After he gets the report, McNamara then has 30 days to hold a hearing.

Brad Putnam, the victims’ brother, said Wednesday that he and his wife have adopted the Steeles’ two children. He said the kids are doing well, but he wants them to be able to move on.

“I just wish it didn’t have to keep being brought up,” he said of the case. “We’re a bit angry.”