Alfredo Simón is likely to spend the next year of his life behind bars.
The Baltimore Orioles reliever was denied bail on involuntary manslaughter charges.
Defense attorney Dinosa Dilone said she plans to appeal Tuesday's ruling.
Simón, 29, has been locked up because a shooting on New Year's Eve in his native Dominican Republic that left a 25-year-old man dead and his 17-year-old brother injured.
Simón's lawyer has said he was firing celebratory shots in the air. A bullet killed Michel Castillo, and injured his brother, Starlling Castillo, in the city of Luperón in Puerto Plata.
A judge had earlier ruled that Simón could be held for up to a year pending trial.
Simón joined Baltimore in 2008 but was quickly sidelined with an injury. He went 4-2 with a 4.93 ERA last season and had 17 saves.
Based on reporting by the Associated Press.