Police say a 57-year-old Brooklyn man was arrested and charged with murder for fatally shooting another man on Christmas Eve in Brownsville.

Shamar Williams is accused of opening fire on 47-year-old Marcin Iwanowicz, a Polish immigrant.

Authorities say officers discovered Iwanowicz with a gunshot wound to the chest in front of Powell Street and Belmont Avenue just before 10 a.m.

EMS took Iwanowicz to One Brooklyn Health-Brookdale University Hospital Medical Center, where he died.

The shooting happened outside of the St. Jude Clinic, where Iwanowicz had been going for treatment.

News 12 spoke with Iwanowicz’s father, Stanislaw, who said his son left their Midwood apartment earlier that morning and told him he would return by 10 a.m.

Stanislaw says that around 9 p.m. that night, police came to the family’s home and told them the grave news.

“I didn’t sleep all night. I just cried half of the night. I didn’t eat nothing,” his father said. “I’m old, you know… if you’re young, you take everything differently. What am I supposed to do… to die?”

Police say Williams faces additional charges, including robbery and criminal possession of a weapon.

The NYPD could not provide additional information regarding the robbery charge.