The 98-year-old actor wrote a blog post for The Huffington Post describing his feelings of triumph, and eventual disappointment and shame, after his first – and only – wild game hunt in Kenya about 50 years ago.
"I remember being drunk with power as I softly pulled the trigger of my high-powered rifle and watched a leopard, a gazelle, an oryx, a zebra and other defenseless animals fall to the ground," he wrote.
A photographer was present, documenting the trip for a book called Great Hunts and the animals Douglas killed were shipped home and mounted in his projection room.
"One day I looked up and all my trophies seemed to be staring at me," Douglas continues. "I realized how obscene it was to kill them. I quickly got rid of all the 'trophies' and tried to forget the sin that I had committed."
After seeing the outcry over Cecil's killing in Zimbabwe, Douglas believes that Dr. Walter Palmer, the man responsible for the lion's death, is definitely paying for his "inexcusable" actions, and he feels sorry for the Minnesota dentist.
"He is being hunted much like he stalked his prey," Douglas wrote. "But he is not alone, many people hunt and kill wild animals for sport. That must be stopped."
Watch Blindfolded People's Reactions to Petting Exotic Animals
Zimbabwe officials are seeking to extradite Palmer for killing the lion that was allegedly lured of a national park in July and illegally killed.
Palmer, who has been caught in a social media firestorm that prompted him to close his business, has said in previous statements that he regrets killing the 13-year-old lion, who was part of a university study, and that he thought the hunt was legal.