DENVER—Ishmael Petty, age 46, an inmate at the USP Florence Administrative Maximum Security Prison (ADX) in Florence, Colorado, was found guilty today following a two day jury trial of three counts of assault, resisting and impeding a federal employee using a dangerous weapon resulting in bodily injury, the U.S. Attorney’s Office, the Federal Bureau of Investigation (FBI) and the Federal Bureau of Prisons (BOP) announced. The jury deliberated for one hour and twenty minutes before reaching their unanimous guilty verdicts. The jury trial was heard before U.S. District Court Judge Philip A. Brimmer. Petty is scheduled to be sentenced by Judge Brimmer on October 30, 2015.

Petty was indicted by a federal grand jury on January 27, 2015. The jury trial began on July 13, 2015. It concluded today, July 14, 2015.

According to court documents, and evidence presented at trial, on September 11, 2013, Petty, who was serving a life sentence at ADX for killing his 71 year old cell mate at the United States Penitentiary Pollock in Louisiana, attacked two BOP librarians and a case manager as they were delivering books to his cell. At ADX there is an outer door, a secure area, and then an inner door before entering the actual cell. While the BOP employees believed that Petty was in his cell, he was in fact hiding in the area between the outer and inner doors. He was wearing self-made body armor, consisting of cardboard box like material, and had a weapon, specifically a shank. When the attack began, Petty threw hot sauce in the eyes of one BOP librarian, and then attacked the other librarian. The third BOP employee, a case manager, quickly came to their aid and called for help. One of the BOP employees used their baton to try and subdue Petty. Petty ultimately took control of two batons and used them in his attack. Once the call for help was made Petty went back into his cell.

Prior to Petty’s life sentence for killing his cellmate, he was sentenced to federal prison for 420 months for an elaborate armed bank robbery in Mississippi where he was wearing a police officer’s uniform.

“Defendant stands convicted of a cowardly and brutal assault on defenseless staff at ADX. The defendant, who was serving time at ADX for murdering his cellmate at another prison, ambushed and brutally assaulted two staff librarians, using his much greater size to injure the older of the two severely and permanently,” said U.S. Attorney John Walsh. “Only the courageous intervention of a third staff member prevented the defendant from killing that librarian.”

Petty, who is currently serving a life sentence, faces not more than 20 years in prison, and up to a $250,000 fine per count for each of the three counts of conviction.

This case was investigated by the FBI with support from the Federal Bureau of Prisons.

This trial was handled by Assistant U.S. Attorneys Colleen Covell and Rebecca Weber.