Alabama’s understaffed and overcrowded prisons have for years allowed killings, sex abuse and other violence to go largely unchecked , according to a scathing set of findings issued Wednesday by Justice Department investigators.

The investigators found reasonable cause to suspect the state “routinely violates the constitutional rights of prisoners housed in Alabama’s prisons by failing to protect them from prisoner-on-prisoner violence and prisoner-on-prisoner sexual abuse, and by failing to provide safe conditions,” Justice Department officials wrote in a letter to Gov. Kay Ivey.

Federal authorities called the violations “severe, systemic, and exacerbated by serious deficiencies in staffing and supervision,” as well as an inability to control the flow of drugs and weapons inside the 13-prison system that holds roughly 16,000 male inmates.

To highlight the problem, investigators cited as an example a single week in September 2017 in which Alabama’s prisons saw a killing, three stabbings, a half-dozen severe beatings, two drug cases, four sex-abuse incidents, and a fatal drug overdose.

Alabama’s prisons have the highest homicide rate in the country, according to officials who also noted that some killings there went unreported.

According to public reports from the Alabama Department of Corrections, 24 prisoners were killed between January 2015 and June 2018, but federal investigators concluded at least three additional homicides had gone unreported as such.

“There are numerous instances where ADOC incident reports classified deaths as due to ‘natural’ causes when, in actuality, the deaths were likely caused by prisoner-on-prisoner violence,” the Justice Department report concluded.

Federal authorities also faulted state officials for what they said was a failure to fully investigate sex assaults in prison.

The Alabama prison system “has a tendency to dismiss claims of sexual abuse by gay prisoners as consensual ‘homosexual activity’ without further investigation, implying that a gay man cannot be raped,” the report found, adding that some inmates who reported being assaulted were asked to sign a release of liability document by prison officials.

Conditions in Alabama prisons amount to a violation of the Constitution’s Eighth Amendment protections against “cruel and unusual punishment,” the Justice Department found. In their letter to the governor, federal investigators said they may file a lawsuit within 49 days to force changes inside the prisons but would prefer to negotiate a settlement with the state.

In a statement, the governor said she plans to work closely with the Justice Department “to ensure that our mutual concerns are addressed and that we remain steadfast in our commitment to public safety, making certain that this Alabama problem has an Alabama solution.”

The investigation began in October 2016, a time when the Obama administration was a proponent of such “pattern and practice” investigations into law enforcement agencies with troubling track records of civil rights violations or mistreatment.

It continued during the Trump administration, despite then-Attorney General Jeff Sessions’s public statements critical of such work. Until his departure late last year, Sessions had sought to curtail pattern and practice probes in favor of criminal investigations of individuals who may have violated people’s rights.

Understaffing at the Alabama prisons, and the imposition of “voluntary mandatory overtime” on the skeleton prison staffs, have contributed to the problems, according to the Justice Department, which recommends immediately hiring 500 new guards to deal with the shortages.

Even that may not be enough, the report warns, noting that in February, Alabama filed a report indicating it needed to hire more than 2,300 people in the next four years.

“These staggering staffing deficiencies,” the Justice Department noted, “were determined by ADOC’s own experts.”