HOUSTON (AP) — Authorities on Wednesday identified a man who they believe gunned down one of former President George H.W. Bush’s doctors last month as the son of a woman who died while the doctor was operating on her more than 20 years ago.

Houston police Chief Art Acevedo said at a news conference Wednesday that the suspect, 65-year-old Joseph James Pappas, should be considered armed, dangerous and possibly suicidal.

“There was a lot of planning that went into this. There was a lot of planning and, sadly, some skill,” Acevedo said of the attack on Dr. Mark Hausknecht, who was gunned down July 20 while riding his bike to work. Authorities say the shooter rode past Hausknecht before turning around and firing.

Acevedo said Pappas is white and very fit and that he likely has his 10-speed bicycle, which he rides “extensively and almost exclusively.”

In 2000, Hausknecht treated Bush for an irregular heartbeat after the ex-president complained about lightheadedness.