A dragnet of federal, state and local law enforcement is on the hunt for the gunman who fatally shot a federal court judge’s son and wounded her husband – all while disguised as a FedEx worker – at their New Jersey home Sunday night, officials announced Monday.

U.S. District Judge Esther Salas’ son, 20-year-old Daniel Anderl, was killed and her husband, defense lawyer Mark Anderl, 63, is in the hospital after the men were shot in the doorway of their North Brunswick home around 5 p.m. Sunday, officials have said.

The son of U.S. District Judge Esther Salas was killed Sunday and her husband was in critical condition after they were shot at their home in New Jersey, senior law enforcement officials told NBC New York.

The shooting occurred in North Brunswick Township early in the evening, the FBI said in a statement, adding that it was searching for one suspect.

The son of U.S. District Court Judge Esther Salas was fatally shot and her husband critically wounded when a gunman dressed as a FedEx driver entered her home near North Brunswick, N.J., Sunday afternoon, according to local media.

Salas was reportedly unharmed in the attack, the New Jersey Globe reports. Daniel Anderl, Salas' 20-year-old son, was killed. Her husband, Mark Anderl, a criminal defense attorney and former assistant Essex County prosecutor, reportedly underwent surgery at Robert Wood Johnson Hospital in New Brunswick and was listed in critical but stable condition.