SACRAMENTO, Calif. -- A psychiatric hospital worker is accused of raping a "gravely disabled" teen in mid-March.

A sperm sample from Sunday Adeife, 42, matched evidence taken from the 17-year-old girl's vaginal swab, according to an affidavit by the U.S attorney's office.

The affidavit was released to KCRA 3 by Abraham Arredondo, a spokesman with the California attorney general's office.

The girl, identified only as Samantha J., was admitted March 8 to Heritage Oaks Hospital because she was "gravely disabled" and couldn't take care of herself, the affidavit said.

Samantha J. alleged that on her second night at the hospital, she was sexually assaulted and fondled.

"When someone takes advantage of someone who can't take care of themselves and sexually molests them, that's pretty severe," said Larry Menard of the state Department of Justice.

The girl described her attacker as an African man with dark hair, a "fade"-style haircut, a mustache, an "African" accent, and she said he was wearing a cologne or aftershave she thought she could identify.

The document also said Adeife was seen on surveillance video entering Samantha J.'s room in mid-March.

According to the affidavit, Adeife had denied touching the patient and agreed to a buccal swab for DNA evidence.

Authorities said they fear there may be more victims out there.

"The same person had been investigated by us at another mental health facility," Menard said. "But we weren't able at that time to prove anything."

Adeife was arrested Monday at his apartment in the 2600 block of Howe Avenue.

He is being held on a $600,000 bail at the Sacramento County Jail and is scheduled to appear in court Wednesday.

Investigators said that anyone who thinks they may have been molested by Adeife should come forward.