Bike to bike? Seems targeted. Wonder if he biked a route every day. The doctor worked at Texas Orthopedic Hospital which is less than a mile from where he was shot. He was headed to Houston Methodist Hospital and all is right around each other. Seems as if he rode his bike between all the medical buildings to appointments so he would have been a familiar sight. https://www.cbsnews.com/news/mark-hausknecht-cardiologist-shot-killed-today-texas-medical-center-2018-07-20/
That neighborhood is like medical complex central. Lots of medical facilities around. Residents are majority black.
http://abc13.com/houston-doctor-shot-to-death-by-gunman-on-bike-identified/3794217/ “8:50 am... The suspect was described as a white or Hispanic man wearing a dark jacket. Police said the suspect had a tan baseball cap, sunglasses and was clean shaven.”
It does seem targeted, but it’s odd. Shooting while turned on a bicycle can’t be good for accuracy. The doctor initially survived and was able to summon help.
I think if you wanted to assassinate somebody, there would be better ways.