A shocking video clip has emerged from an Arizona prison apparently showing an inmate’s brutal attack on a librarian.

According to KTRK, the incident occurred in December when inmate Timothy Monk allegedly retrieved a shank from his shoe and put Allen Hartzell in a headlock.

CBS reports that Monk’s alleged motive for the incident was a desire to be released early from a 97-year prison sentence stemming from a 1988 conviction on charges of sexual assault, robbery and kidnapping.

The librarian was reportedly able to grab his pepper spray and deployed the nonlethal weapon during the attack.

Authorities described the knife used in the attack as a cutting device fashioned behind bars that had been concealed in Monk’s sock.

He allegedly held the knife to Hartzell’s neck as he held the librarian hostage, moving to a corner of the library as a team of tactical officers arrived to negotiate with the inmate.

“I told you I’d show you how bad I am,” said the man identified as Monk. “Why do I gotta do this?”

Another voice asked if the inmate was sick to his stomach, to which the man responded yes.

“That’s from the pepper spray,” the hostage negotiator can be heard saying.

“Probably,” the prisoner replied.

A short time later, officers threw a flash grenade into the library to cause a disruption and make their way inside to rescue Hartzell. The librarian was transported out of the room safely as officers reportedly restrained Monk and led him away in handcuffs.

Authorities are describing the claims surrounding this video “reprehensible criminal actions” on Monk’s part, adding that he will face new charges related to the incident.

[Featured image: Arizona Department of Corrections, video screenshot]