A gunman dressed as a delivery driver shot and killed the son of a federal judge and wounded her husband at their New Jersey home on Sunday, law enforcement confirmed to The Washington Post.

U.S. District Judge Esther Salas was not injured in the shooting, which the FBI, the U.S. Marshals Service and local authorities are investigating.

The gunman showed up to Salas’s home in North Brunswick, N.J., wearing an outfit described to police as a FedEx uniform, law enforcement said. Both Mark Anderl, 63, a defense attorney and former Essex County assistant prosecutor, and Daniel Anderl, 20, a student at Catholic University in D.C., were shot after one of them opened the door for the gunman around 5 p.m., ABC News reported.

“He was shot through the heart,” North Brunswick Mayor Francis “Mac” Womack (D) told ABC News of Daniel Anderl.

Salas’s son died and her husband was rushed to the hospital for surgery, the Associated Press reported. Mark Anderl is now in stable condition, Womack told NJ Advance Media.

The FBI said it is looking for one suspect. The Marshals Service said it is also investigating, adding in a statement to HuffPost that the agency “is responsible for the protection of federal judicial officials and we take that responsibility very seriously.”

Authorities have not given any indication of a motive in the shooting. Womack, who is friends with Salas and her husband, told ABC he wasn’t aware of any specific threat against the judge.

“As a judge, she had threats from time to time, but everyone is saying that recently there had not been any,” Womack said.

Salas, 51, was New Jersey’s first Hispanic woman to serve as a U.S. district judge. President Barack Obama nominated her for the position in 2010, and she was confirmed by the Senate in 2011. Salas previously served as a magistrate judge for the U.S. District Court for the District of New Jersey.

She has presided over a number of high-profile cases, including the criminal trial of “The Real Housewives of New Jersey” stars Joe and Teresa Giudice. Salas sentenced them each to prison for crimes including tax evasion.

She’s been on the bench for recent cases involving the Grape Street Crips, according to NJ Advance Media, a gang charged with running a drug trafficking operation. Salas has more recently taken on a lawsuit brought by Deutsche Bank investors alleging the bank failed to follow its anti-money-laundering policies by taking on “high-risk” clients including Jeffrey Epstein, the convicted sex offender, the AP reported.

Sen. Robert Menendez (D-N.J.) appealed for a quick arrest in the Sunday shooting.

“I know Judge Salas and her husband well and was proud to recommend her to President Obama for nomination to New Jersey’s federal bench,” Menendez said in a statement. “My prayers are with Judge Salas and her family, and that those responsible for this horrendous act are swiftly apprehended and brought to justice.”

New Jersey Gov. Phil Murphy (D) added in a statement, “Judge Salas and her family are in our thoughts at this time as they cope with this senseless act.”