Joseph Maldonado-Passage, who goes by "Joe Exotic," also was sentenced for crimes that included killing several tigers and falsifying wildlife records

A former Oklahoma zookeeper found guilty in a murder-for-hire plot to kill a rival animal-rights activist was sentenced Wednesday to serve 22 years in prison for that and other crimes, which included killing tigers to make room for more big cats at his exotic animal park.

The sentence followed the April 2019 conviction of Joseph Maldonado-Passage, a country music singer who goes by the name “Joe Exotic” and previously ran, without success, for president and Oklahoma governor, reports Oklahoma City TV station KOCO.

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The U.S. Attorney’s Office for the Western District of Oklahoma confirmed the sentencing to PEOPLE.

Starting in July 2016, according to prosecutors, Maldonado-Passage repeatedly tried to hire people — one of whom was an undercover FBI agent — to murder Carole Baskin, who owns a tiger refuge in Florida and won a multimillion-dollar judgment against Maldonado-Passage’s G.W. Exotic Animal Memorial Park in Wynnewood, Oklahoma.

Maldonado-Passage eventually gave a man $3,000 to travel from Oklahoma to South Carolina and on to Florida to kill Baskin, “with a promise to pay thousands more after the deed,” according to the U.S. Attorney’s Office.

Image zoom Joseph Maldonado-Passage JoeExoticTV/Youtube

Separately, authorities said Maldonado-Passage killed five tigers in October 2017 to free up cage space for other animals, sold and offered to sell tiger cubs in interstate commerce, and falsified forms involving the sale of wildlife in interstate commerce.

In his defense, Maldonado-Passage said he killed the animals for humane reasons.

“I put five tigers to sleep because they were in pain,” he told KOCO in November 2018. “They were in pain. They had toenails coming out of their ankles. They had no teeth. They had exposed root canals.”

He served as his own attorney in a federal trial where a jury found him guilty of two counts of murder-for-hire, eight counts of violating the Lacey Act for falsifying wildlife records, and nine counts of violating the Endangered Species Act.

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“The self-described Tiger King was not above the law,” First Assistant U.S. Attorney Robert J. Troester said in a statement after the conviction. “Rather, the jury only needed a few hours of deliberation before finding him guilty of engaging in a murder-for-hire plot to kill a rival and violating federal laws intended to protect wildlife when he killed multiple tigers, sold tiger cubs, and falsified wildlife records.”