(Associated Press) – A federal inmate was charged Friday with attempted murder in the Nov. 24 prison stabbing of Derek Chauvin, the former Minneapolis police officer convicted of murdering George Floyd.

Federal prosecutors say John Turscak stabbed Chauvin 22 times in the law library at the Federal Correctional Institution in Tucson, Arizona, with an improvised knife.

Prosecutors say he told correctional officers he would have killed Chauvin had they not responded so quickly.

Prosecutors also say Turscak later denied wanting to kill Chauvin.

A lawyer for Turscak was not listed in court records.

Turscak has represented himself from prison in numerous court matters.

After the stabbing, he was moved to an adjacent federal penitentiary in Tucson.