Mom: Dumping Dead Body 'Stupidest Thing' I Ever Did Sandra Inman said her son accidentally killed his estranged wife By Mark Russell, Newser Staff Posted Mar 1, 2013 10:44 AM CST 22 comments Comments Sandra Inman, in just unsealed testimony, said her son's killing of his estranged wife was an accident. She also regretted her decision to help her son hide the body in a septic tank. (WSYX Columbus) (Newser) – The Ohio murder occurred nearly two years ago, but just unsealed transcripts of her taped confession reveal some truly grim rationalizing by the killer's mother. Sandra Inman told investigators that she wanted to see her grandchildren more so she came up with the idea of forcing her son's estranged wife into a car to talk about it. But after son Will forced the 25-year-old into the backseat, he put a zip tie around her neck and accidentally strangled her. "I know, I know positively, he didn't do it on purpose," said Inman, according to the AP. Inman said it was her idea to dump her daughter-in-law's body in a septic tank behind a church before vacuuming out the car. "It's the stupidest thing I ever thought of to do in my whole entire life," said Inman. She was sentenced to 15 years to life in prison after pleading guilty to murder and other charges. Her husband and son were sentenced to life in prison for their roles in the murder.