Greg Halman was killed in the early hours of the morning on Nov. 21, and his brother Jason Halman has been in custody since.
Details of Halman's case began to filter out about on Tuesday, the day after the 24-year-old Dutch outfielder was found stabbed to death in his homeland.
Police told the AP that an argument about loud music may have precipitated the dispute, which resulted in Halman's death and his brother's arrest.
Most of the details of the attack remain shrouded in mystery, but police spokeswoman Patricia Wessels told the AP that loud music "appears to be the reason the victim walked downstairs." Police are still interviewing Jason Halman and are still trying to piece together what happened.
Halman, who was born in Haarlem and passed away in Rotterdam of the Netherlands, batted .230 with two home runs for the Mariners this season. Seattle's Minor League Player of the Year in 2008 had distinguished himself as an ambassador for baseball in Europe.
Earlier in the winter, Halman -- along with fellow Dutch big leaguer Rick VandenHurk -- volunteered to be part of the European Big League Tour, a series of instructional clinics for children. Halman, like VandenHurk, played for the Netherlands at the 2009 World Baseball Classic.
Halman was part of an athletic family that included his father, Eddy Halman, who played baseball in Holland's highest league. Jason Halman also played baseball in Holland, and their sister, Naomi, is a pro basketball player in Europe.
Former Major Leaguer Robert Eenhorn, who's currently employed as the technical director of the Dutch baseball association, spoke for many when he said he was devastated by the news.
"The only thing I can say right now is we are deeply shocked," Eenhorn told the AP. "All our thoughts are with his family and how they are going to have to deal with this tremendous loss."
Spencer Fordin is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.