him the best driver he ever had, was determined to find out what was wrong. "He could remember everything from 1970 back, nothing forward," Johnson said. "And, it seemed like it just happened all at once. You'd go to dinner with him, and they'd put a plate of food in front of him, and he'd just sit, and look at it, until you said, 'Lee Roy, eat.' Then, he’d pick up his knife and fork." Yarbrough showed well in a few Indy Car starts, leading the inaugural California 500 at Ontario Motor Speedway late before dropping out, and then finishing 3rd at Trenton Speedway in 1971. After competing in 3 Indianapolis 500s in 1967, '69 and '70, Yarbrough was driving a Dan Gurney Eagle in practice for the 1971 500 when he spun and crashed hard in turn one. Yarbrough spent the next few months, June through November, in and out of the hospital with many different ailments and memory problems. He was rumoured to have contracted Rocky Mountain spotted fever from a tick bite, and also drank alcohol heavily. He most likely suffered brain trauma from the crashes in Texas and Indianapolis. Many drivers would have different theories on the cause of Yarbrough's declining mental health, one example being Ray Fox saying “Racing happened to Lee Roy. Just too many crashes. And they sent him off the deep end.” James Hylton would blame “that doggone tick. The Rocky Mountain spotted fever—if it goes untreated, it’s a mental thing, and it’ll drive you insane. They gave Lee Roy so much medication when they finally did treat it that it eventually caused his death. He just deteriorated to the point where he was unmanageable. The man did not deserve that. Lee Roy was one of the good ones.” On a Thursday evening in February 1980, Yarbrough and his mother, Minnie were watching TV together when out of nowhere, Yarbrough would say "Mother, I hate to do this to you." Minnie replied, "What do you mean?" Yarbrough would proceed to strangle his mother, who was only saved by a nephew who had heard the screams and hit Yarbrough with a jelly jar on the head. A few minutes later, police arrested Yarbrough with charges of first-degree attempted murder for trying to kill his 65-year-old mother, plus assault on a police officer. Yarbrough was committed to the Florida State Hospital at Chattahoochee by