A couple died of suicide after Tucson police say they killed their adult son with nitrogen.
During a welfare check about 10:45 p.m. Oct. 7, the couple â Robert Gary Stern, 74, and his wife Deborah Lee Stern, 73 â were found dead on the back porch of their Miramonte neighborhood home in the 3300 block of East Fourth Street, Tucson police said Friday in a news release.
The couple had each been shot, and police deemed their deaths suicide, the release said.
Officers then found the body of their son, Shane Isadore Stern, 51, inside the house.
An autopsy later determined Shane Stern died of nitrogen-induced asphyxia, the release said.
Investigators say it appears the couple administered nitrogen to their son, who had Down Syndrome and a "declining" quality of life. The pair then went to the porch and died from suicide, the release said.
"The totality of the circumstances indicate that this situation was planned," police said in the release.
The investigation continues. Anyone with information is asked to contact the department or 88-CRIME, the anonymous tip line.
