The vehicle of a White Plains firefighter accused in a deadly wrong-way crash has been impounded and authorities are testing a suspicious substance that was found inside his SUV.

Commissioner of Public Safety David E. Chong told on Friday morning that a search warrant recovered a suspicious substance inside. The substance is being tested at the county lab.

Firefighter Erik Refvik was off duty when he allegedly crashed into a Honda Monday in downtown White Plains. He is charged with criminally negligent homicide and DWI. Depending on what the investigation determines, police say Refvik could face more charges. He was released from the Westchester County Jail after posting $25,000 bail.

He is accused of killing 47-year-old Reyda LaMadrid, a mother of two teenagers, and seriously injuring her husband, 49-year-old Edgar Lopez. Friends have set up a website for donations to help the family send her body home to Peru.

Refvik was hired by the White Plains Fire Department in 2010 and has had a clean disciplinary record, until now. He has been suspended.