Police Commissioner Celvin Walwyn told The Associated Press that officers had gone to the home of Winston C. Brown because he had kidnapped his estranged wife and sister and was threatening them with a knife and an ice pick.
After a standoff Tuesday morning in St. Kitts, Brown released his wife, who had been stabbed and beaten, and then lunged at one of the police officers, stabbing him just above his knee, Walwyn said. The officer then opened fire and shot the 40-year-old Brown, who died at the scene.
The officer has been placed on desk duty pending an investigation.
"If the police had wanted to kill him they would have done it sooner. Once he stabbed the officer, all bets were off," Walwyn said. "It was a clear-cut case of self-defence."
Brown and the 36-year-old Collins had the same mother, Florence Skeeter Collins, but different fathers. A funeral for Brown is scheduled for Feb. 1.
Collins has represented St. Kitts and Nevis in four Olympics and is one of the country's most prominent athletes. He carried the flag for his country at the opening ceremony of the London Olympics but was taken off the team for missing training. He said he was stressed by life in the Olympic village and wanted peace and quiet with his wife before racing.