A D.C. firefighter is facing hate crime charges after allegedly tailgating a truck in Pennsylvania and lobbing racial slurs and threats at the drivers.

Adam Kraus, a 32-year-old firefighter who started working for D.C. Fire and EMS in June 2015, is charged under Pennsylvania’s hate crime statute with ethnic intimidation.

Kraus allegedly was driving outside Harrisburg in Lower Allen Township June 30, according to court records.

Court records say Kraus was driving his pickup truck on Route 15 behind a car occupied by two African-American people. At some point, Kraus began flashing his high beams.

Then the cars stopped at an intersection, Kraus waived a handgun in the air and started yelling at the two occupants of the car. He also used a racial slur, according to court documents.

Kraus was off-duty at the time, but didn’t report it to the D.C. fire department as required. The incident was discovered during a routine background check.

D.C. Fire issued a statement saying the department was aware of the criminal charges and that Kraus is on leave pending the outcome of his criminal proceedings.

Kraus did not respond to a request for comment.