GLENWOOD (AP) — The first of six former Glenwood State Resource Center workers charged with mistreating facility residents has been convicted of abusing a severely autistic man.

The Des Moines Register reports that 24-year-old Kayla Stevenson was convicted Tuesday in Mills County District Court of wanton neglect of a resident. She faces up to two years in prison when she's sentenced.

A video shown at her trial showed Stevenson hitting the 19-year-old resident in the head twice with the heavy end of a butter knife as he's held down by another worker. Her attorney argued the incident amounted only to "taps" on the head that caused no injury.

Earlier this year, 13 workers at the center quit or were fired over abuse allegations. An Iowa Department of Human Services investigation that found several clients were physically abused or subjected to verbal abuse or neglect.

The center provides services for those with intellectual or developmental disabilities.