The next month, according to prosecutors, Mr. Maldonado-Passage — who is known as Joe Exotic and ran for president as an Independent in 2016 and for governor of Oklahoma in 2018 — met another man and arranged to have him kill Ms. Baskin. That man turned out to be an undercover F.B.I. agent, the Justice Department said.

Image Joseph Maldonado-Passage tried several times to hire someone to murder an animal-rights activist. On his final attempt he hired an undercover F.B.I. agent. Credit... Santa Rosa County Jail, via Associated Press

Ms. Baskin, who had earlier won a million-dollar civil judgment against Mr. Maldonado-Passage and runs Big Cat Rescue, a nonprofit, 69-acre, big cat sanctuary in Florida, said Wednesday that she had lived in fear because of Mr. Maldonado-Passage.

“The evidence showed that over the course of many years, he has tried to coerce others into killing me, and in the end, resorted to hiring others to kill me,” Ms. Baskin said in a video posted on the Big Cat Rescue website.

“Because of his constant threats to kill me, I have found myself seeing every bystander as a potential threat,” Ms. Baskin said. “My daughter, my husband, my mother, my staff and volunteers have all been in peril because of his obsession with seeing me dead.”

Mr. Maldonado-Passage, whose lawyers declined to comment on the sentence, said in a Facebook post that he maintained his innocence and planned to appeal.