The shooting happened around 12:30am Saturday at 23 Largo in Hitchcock's gated Harborwalk community.
Hitchcock police tell us 63-year-old Dennis Roy Redding of Cedar Creek was arrested and charged with the murder of Dr. Mark K. Holcomb, 61.
Police said Redding is a former Houston police officer. More recently, he worked security for the NASA Johnson Space Center.
According to investigators, Redding and Holcomb were old friends. They had some sort of falling out and were working on getting over the past.
But police said the past was brought up Saturday night. That's when Redding grabbed a gun from his suitcase and shot Holcomb in the stomach.
Holcomb was the owner of Clear Lake Oral And Maxillofacial Surgury in Webster.
Redding was being held Sunday at Galveston County Jail with bond set at $150,000.
This is Hitchcock's first homicide since 2010.