Suffolk County police arrested a South Setauket man Monday for allegedly assaulting his infant son.

They say they were called to Stony Brook University Hospital on Jan. 21 when the child was brought into the emergency department with injuries consistent with abuse.

Following an investigation by Special Victim's Section detectives, Vincent DiStasi was arrested at the hospital where the 5-week-old is in critical condition.

The 31-year-old was charged with first degree assault, reckless assault of a child and endangering the welfare of a child.