The Coconino County Sheriff’s Office has released more information on Monday’s incident on Highway 89 near Gray Mountain. Officials say 35-year-old Richard Osburn from Oklahoma was with his wife, and was traveling southbound on the highway, when it drifted into the northbound lane near the Sinagua Trading Post. He attempted to correct his position and went across the median, causing damage to his car. Soon after,a couple from Arkansas stopped to help. Osburn approached them in an aggressive matter, so the couple got back into their vehicle. While pulling back onto the highway, Osburn ran and jumped onto the hood of the vehicle. The female then started to drive southbound on Highway 89. Osburn took out a fixed blade knife and smashed the glass sunroof out of the victim’s vehicle. He then went partially into the vehicle and tried stabbing the woman. The male was able to push Osburn back out of the sunroof. The man suffered a minor injury in the struggle. The woman then swerved and Osburn fell off the vehicle and onto the road. A preliminary autopsy suggests Osburn died from blunt force trauma to the head, most likely when he hit the highway after falling off. Osburn’s family tells KAFF News that Osburn was a disabled veteran who suffered from PTSD. They think that is what caused him to react the way he did after the accident. Osburn’s wife was interviewed by detectives and has been cooperative with the investigation. She was released to a friend and Victim Witness services. The incident remains under investigation.