An arbitrator has reversed the firing a year ago of Stillwater prison’s warden for sending sexually graphic e-mails from his official account and other troubling behavior, but the state Department of Corrections said Thursday that it is weighing its options for how to respond.

Steve Hammer lost his job running one of the state’s largest prisons for what the department said was a violation of various policies. Prison officials haven’t provided further explanation, but a cache of documents obtained by the Star Tribune revealed that lewd e-mails, bullying and other improper behavior preceded his ouster.

Hammer challenged his firing, and corrections officials were notified Tuesday that the arbitrator “granted his grievance and awarded him reinstatement,” said department spokeswoman Sarah Fitzgerald.

She said the department is choosing not to release a copy of the ruling pending further review. The state agency overseeing the dispute, the Bureau of Mediation Services, also has yet to make the ruling publicly available.

She declined to address when Hammer might return to duty, saying, “The department is currently reviewing the decision and next steps.” The prison’s website still lists Eddie Miles as warden.

Victor Wanchena, associate warden at Stillwater, said late Thursday morning that Miles’ status of warden has not yet changed.

As for Hammer’s future at Stillwater, Wanchena said, “I have no information on when he’ll return. ... I have no knowledge of what the terms are in [his] return.”

Hammer, who first joined the Minnesota prison system in 1991, could not be immediately reached for comment.

On Friday morning, attorney Gregg Corwin contacted the Star Tribune on behalf of Hammer and provided a copy of the arbitrator's ruling. The arbitrator wrote that the quality of Hammer's work as a warden was excellent and that the department failed to show sufficient "just cause" to fire him for his personal conduct.

The documents from an investigation by the Department of Corrections (DOC) included one e-mail exchange Hammer had in April 2014 with a female former employee during which he discussed his transfer to Stillwater from the Rush City prison. The move happened after corrections officials there discovered he was having an improper relationship with an employee.

Hammer wrote of the Stillwater prison, “I’m not happy I hate that place.”

The ex-employee replied that she would be an “awesome secretary,” and Hammer replied, “Hmmm secretary? I’m thinking Naughty thoughts.”

He wrote several more explicit e-mails around that time to non-employees using his official account, the investigation revealed. He also received a nude photo of a woman, which he did not report.

In one e-mail exchange from July 2014, Hammer wrote, “Mine misses you.” The woman asked him to clarify, and he replied, “Head Heart Body Penis Not Necessarily in the order Have you been photogenic lately?”

The same e-mail thread suggested “Face time naked?” She went on to say, “No naughty pics.”

The investigation also uncovered instances of Hammer intimidating or abusing employees. In one case Hammer lashed out at an employee who filed a harassment complaint. His face turned red, and he tore up the complaint in front of the employee.