A South Carolina woman was convicted Thursday of causing the death of her 14-month grandson by putting an opioid pain medication in the child's sippy cup, WMTW reported.

Angela Denise Brewer, 46, was found guilty of homicide by child abuse.

by a Pickens County jury and was sentenced to 20 years in prison, WMTW reported.

Brewer was the sole caregiver of the toddler when the boy was found unresponsive on Oct. 17, 2014. When deputies arrived, a family member was performing CPR on the boy, WMTW reported. The child was taken to a hospital, where he was pronounced dead.

The coroner performed an autopsy, and it was determined that the opiate Oxycontin was found in his system. Investigators also found Oxycontin in the child’s sippy cup, WMTW reported.