Sandra Inman, 47, told investigators in 2011 that she wanted to see her grandchildren more so she came up with the idea of forcing her daughter-in-law into the car in Logan so they could discuss the issue, according to a transcript of the interview. Once Summer Inman was forced into the back seat, her wrists were bound with zip ties.
Sandra Inman said her son, William "Will" Inman II, put a zip around his 25-year-old wife's neck and accidentally strangled her as she struggled. Sandra Inman said they couldn't find a knife or anything else in the car to cut off the zip.
"I know, I know positively, he didn't do it on purpose," Sandra Inman told investigators.
Afterward, Sandra Inman said it was her idea to dump the body in a septic tank behind a church before going elsewhere and vacuuming out the inside of the car. During the interview a week after the murder, she instructed investigators where they could find the body.
While the interview with Sandra Inman was continuing, officers at the church unbolted the septic tank lid and reported seeing Summer Inman's leg sticking out in the tank.
"It's the stupidest thing I ever thought of to do in my whole entire life," Sandra Inman told investigators.
The transcript of the March 29, 2011, confession was unsealed Thursday.
Sandra Inman pleaded guilty to murder and other charges and was sentenced to 15 years to life in prison. Her husband, William Inman, 48, was sentenced to life in prison without parole after a jury convicted him earlier this month.
William Inman II, was convicted last year and also sentenced to life in prison without parole.
