According to charging documents, Barker and his wife, Nadine Barker, abused Beatrice Barker, 90, after she granted her son power of attorney, allowing him to access her bank account.
Beatrice Barker died in June 2009.
She was taken to Pioneer Valley Hospital after losing weight and having renal failure and pneumonia, according to charges. Police were called on suspicion of neglect when severe bed sores were discovered.
Investigators learned that Nadine Barker was supposed to care for her mother-in-law, including purchasing her groceries, giving her medication and taking her to the doctor.
She and her husband allegedly hired their daughter-in-law, Angie Barker, to provide daily care at one point, charges state, but Nadine was the main caregiver.
When police served a search warrant at Beatrice Barker's home, 3376 S. Beehive St. (2970 West), they found mold growing in the refrigerator but no food. Prescription bottles littered the floor. The bedroom had only a box spring and mattress on the floor.
Police later determined that Corin Barker had drained his mother's bank accounts of $102,914, leaving just $1,829 in his mother's name on the day of her death.
Corin Barker told investigators that he spent $56,482 of the money "for his own benefit" but spent the rest on his parents' care, according to charges.
He was initially charged with a second-degree felony that would have been punishable by up to 15 years in prison. But prosecutors lessened the charge in a plea deal with Barker.
Nadine Barker was also charged with a second-degree felony. But the charge was dropped in March 2011.
The couple's daughter-in-law, Angie Barker, 39, pleaded guilty to one count of misdemeanor aggravated abuse of a disabled or elderly adult and was ordered to serve probation.
According to court documents, Angie Barker recently violated the terms of her sentence. Her probation officer alleges that she has failed to maintain full-time employment, didn't complete substance abuse treatment and hasn't paid fees and or restitution.
She will appear in court before 3rd District Judge Elizabeth Hruby-Mills at the end of October.