A federal investigation found the Oregon State Hospital failed to keep patients safe from assault.

The Oregon State Hospital, the state’s most secure inpatient psychiatric facility, has only a limited ability to keep its patients safe from each other.

The safety lapses contributed to a serious choking attack, injuries and sexual assaults. The hospital also didn’t adequately investigate the incidents after they happened.

Those are the conclusions of an unannounced, on-site federal investigation conducted at the Salem hospital earlier this year by the Centers for Medicare & Medicaid Services.

CMS opened its investigation in February after receiving four complaints about the hospital.

Oregon Public Broadcasting received its report through a public records request. The report doesn’t detail who filed the complaints, or why, but federal officials opened their investigation a few weeks after a patient assault on Feb. 10.

That day, out of sight of staff, a patient at the hospital picked up another patient and held them in a chokehold until they lost consciousness. The victim in the attack required extensive medical care.

The investigation found other serious incidents of patient-to-patient aggression and failures by staff to adequately supervise their charges.

Investigators also found evidence of sexual assault and sexual contact between patients. About half of the hospitals’ units are mixed gender, where male, female and nonbinary patients live together.

Investigators found that the hospital distributed condoms to any patient who requested them and that, in at least once case, it led a patient to wonder whether sex with peers was permitted at the hospital.

CMS is conducting an additional investigation into an unexpected patient death that occurred this year. The agency hasn’t released that report yet.

The most thoroughly documented incident in the federal safety investigation took place Feb. 10. A patient, referred to only as Patient 23, sat down that morning in a small outdoor courtyard to eat a banana and drink a warm beverage.

Another patient, Patient 22, entered the courtyard.

No one witnessed what took place next, but it was captured on surveillance video, which the federal investigators watched.

“Patient 22 lunged toward Patient 23 from behind, placed their arm around Patient 23′s neck in a ‘chokehold’ manner, and lifted Patient 23 to a standing position,” the investigators wrote.

After a brief struggle, Patient 23′s arms fell to their sides and they went limp. “Over the next 16 seconds Patient 22 maintained the ‘chokehold’ while they also shook Patient 23′s limp body, which was lifted off the ground,” the investigators wrote.

Patient 22 released the chokehold and threw Patient 23 to the ground.

Thirty seconds later, a third patient entered the courtyard, saw Patient 23 lying unconscious on the ground, and called for staff to help. Patient 23 was rushed to the emergency department with a major head injury, and needed extensive medical care over the following weeks.

The federal investigators found numerous lapses of policy related to the attack. For example, staff were supposed to be closely supervising patients in common areas at all times.

At least eight staff were in the unit where the attack took place. Video showed them spending most of their time hanging out at the nursing station, not interacting with and watching patients.

Following the assault, state hospital employees involved in the incident were placed on administrative leave and contract workers were terminated, according to the report.

The report also found considerable warning that Patient 22 might hurt somebody. That patient had been under enhanced supervision and had threatened to kill hospital staff.