Dominican police released a statement indicating they are seeking to question Simon, 29, regarding the early Saturday shooting death of Michael Almonte Castillo, 25, and injuries suffered by the man's 17-year-old brother, Dominican newspaper Al Momento reported.
Police said the shooter immediately fled the incident at a park in Luperon, a small town in the province of Puerto Plata, about 190 miles north of Santo Domingo.
Authorities said they had made telephone contact with Simon and urged him to surrender.
The newspaper said Castillo died of a gunshot wound to the chest while his brother, Estarlin Hernandez Castillo, sustained an injury to his right arm.
Simon, a Dominican native, has played for the Orioles for three years. Last season he posted 17 saves, compiling a 4-2 record and a 4.93 earned run average in 49 games.