OKLAHOMA CITY -- A former Oklahoma zookeeper sentenced to 22 years in prison for his role in a murder-for-hire plot and violating federal wildlife laws has formally requested a pardon.

Attorneys for Joseph Maldonado-Passage, also known as 鈥淛oe Exotic,鈥 filed his application Tuesday with the U.S. Department of Justice. In it, attorneys for Maldonado-Passage, 57, say he maintains his innocence and that he was 鈥渞ailroaded and betrayed鈥 by others.

鈥淛oseph is scheduled to be released from (Bureau of Prisons) custody in 2037; however, with his comprised health, he will likely die in prison," attorneys wrote in the 257-page application. 鈥淗e humbly requests a pardon to correct the injustices he has experienced and to have the opportunity to return to providing meaningful contributions to his community."

The application also includes several character affidavits, letters of support and various trial documents. A spokeswoman for the Department of Justice said it would be premature to comment on the application.

Maldonado-Passage was convicted last year of trying to arrange the killing of a Florida animal sanctuary founder, Carole Baskin, who criticized his treatment of animals. Baskin wasn't harmed. Maldonado-Passage also was convicted of killing five tigers, selling tiger cubs and falsifying wildlife records.

The blond mullet-wearing zookeeper, known for his expletive-laden rants on YouTube and a failed 2018 Oklahoma gubernatorial campaign, is prominently featured in the popular Netflix documentary 鈥淭iger King: Murder, Mayhem and Madness.鈥

Maldonado-Passage is currently housed at the Federal Medical Center, a 1,500-inmate facility in Forth Worth, Texas, prison records show.