A former adviser on criminal justice issues to Sen. Bernie Sanders (I., Vt.) was plotting a violent prison escape, stashing guns and ammunition inside a soon-to-be-opened prison, authorities said this week.

Nashville police said Wednesday that Alex Friedmann, a prison reform advocate who helped shape the Vermont senator's criminal justice agenda, spent months plotting an escape for inmates of the city's detention center. Sanders worked with Friedmann to develop positions on criminal justice in the lead up to his 2016 presidential campaign—positions Sanders still touts.

Davidson County sheriff Daron Hall, at a press conference on Wednesday, said Friedmann hid at least three loaded guns upon breaking into the detention center in December. The break-in was part of "an extremely deliberate and, in my opinion, evil plan" Friedmann developed "over many months," Hall said.

"What disturbed me most is not that this was about an escape, it was also about loss of life," Hall added. "Mr. Friedmann, a convicted felon and self-described criminal justice advocate, planted loaded guns with additional ammunition inside the detention center."

Friedmann, while managing editor at Prison Legal News and associate director at the Human Rights Defense Center (HRDC), helped Sanders go beyond his usual focus on economic issues in 2015. Acting as a consultant for the senator's office, Friedmann called for Sanders to adopt progressive criminal justice positions such as the abolition of private prisons. Sanders's current presidential campaign promises to ban private prisons.

HRDC's 2015 annual report detailed the organization's role in getting the Vermont senator to become more aggressive on the issue.

"Staff at U.S. Senator Bernie Sanders's office consulted with several criminal justice organizations, including HRDC, for a bill he planned to introduce related to the private prison industry," the report stated. "Alex Friedmann participated in multiple conference calls with the senator's staff and suggested the name that was eventually used for the bill, the ‘Justice is Not for Sale Act,'" which aimed to ban private prisons.

Friedmann was arrested last month after he posed as a construction worker, entered the Nashville detention center, stole keys that could open 100 doors, and made a diagram of the jail's layout. He attempted to eat the diagram during his arrest. The facility delayed its opening until April to replace all of the locks. It has now pushed its opening back even further to ensure personnel can do their jobs in a safe and secure environment.

The activist is currently being held on $2.5 million bond at the Tennessee Department of Corrections.

Friedmann was previously arrested in 1987 for armed robbery and assault with attempt to commit murder. In 1991, he was convicted of attempted aggravated robbery and spent 10 years in prison. Friedmann began to battle for prison reform after being paroled in 1999.

Sanders's office did not respond to a request for comment by press time.