LOGAN, OHIO: A mother-in-law of a southeast Ohio woman found strangled in a septic tank has pleaded guilty to all charges related to her daughter-in-law’s death.

Hocking County prosecutor Laina Fetherolf says attorneys reached a plea deal with Sandra Inman, who had pointed authorities to her daughter-in-law’s body.

The 47-year-old Inman pleaded guilty on Thursday to charges of murder, kidnapping, tampering with evidence and gross abuse of a corpse. She was sentenced to 15 years to life in prison.

Inman had earlier pleaded not guilty by reason of insanity to kidnapping 25-year-old Summer Inman in Logan in March 2011.

Authorities say Summer Inman was abducted, strangled with a zip tie and dumped in an underground septic tank in nearby Athens County.

A message seeking comment was left Thursday with Sandra Inman’s attorney.