A former caregiver at a California assisted living community has been convicted of raping an 83-year-old resident with dementia, reports the East Bay Times.

Emeterio Ticar Betiwan, 61, worked the night shift at Diablo Assisted Living in the San Francisco suburb of Walnut Creek. He was convicted of one count of raping a mentally disabled person, one count of a lewd or lascivious act against a dependent person and one count of elder abuse March 9 in part on DNA evidence, the newspaper said, adding that the resident’s family is suing the community. Betiwan reportedly maintained that the sex was consensual although he said “it was a mistake.”

Jill Bragg, who opened the home with her husband, Tom, in 2010, according to ABC7news.com, told police that “she hopes the defendant rots in hell for what he did,” according to the East Bay Times account.