Former NFL linebacker, and hunting partner of Donald Trump Jr., Jason Hairston was reportedly found dead this morning by suicide. According to the New York Post, Hairston, who founded the hunting gear company KUIU, had spoke openly about chronic traumatic encephalopathy (CTE), a degenerative brain disease found in athletes and others who have repetitive brain trauma.

“I played linebacker, and the way I played the game, I led with my head. I played the way they tell us not to play now,” Hairston said in a 2016 interview with CNBC (H/T New York Post). “I have all the symptoms of CTE.”

Trump Jr., who had went hunting with Hairston in Yukon, Canada, just weeks ago, shared a photo of Hairston on his instagram account today along with the following caption: "Jason, I have no words. I will always remember our adventures and sharing a campfire with you. They will be some of my fondest experiences in the outdoors. You were and will continue to be an inspiration to all outdoorsmen and women for generations to come. Thanks for the friendship and the memories buddy. I’m going to miss you. R.I.P"

Hairston was a starting linebacker for the University of California, Davis in college before signing with the Niners as a free agent in 1995. He was traded to the Denver Broncos a year later and retired in 1996, before founding the KUIU hunting clothing company in 2010.