Investigators are examining a possible connection between the shooting and the body of a man found dead from an apparent self-inflicted gunshot wound in Sullivan County, New York, a law enforcement official said.
The man, an attorney from New York City, is being investigated in connection with the shooting, a law enforcement official and a judiciary official told The Associated Press. The man had appeared before the judge in the past, the officials said.
The officials could not discuss an ongoing investigation publicly and spoke to the AP on condition of anonymity.
A gunman posing as a delivery person shot and killed the 20-year-old son of a federal judge and wounded her husband at their New Jersey home before fleeing, according to judiciary officials.
The shooting occurred on Sunday evening at the North Brunswick home of US District Judge Esther Salas, and killed her son, Daniel, said Chief District Judge Freda Wolfson. Her husband, defence lawyer Mark Anderl, was injured in the attack, Wolfson said.
Salas was in the basement at the time and wasn't injured, according to a judiciary official who wasn't authorized to comment and spoke anonymously to the AP.
The perpetrator, believed to be a lone gunman posing as a FedEx delivery person, was not in custody, the official said. The US Marshals and the FBI said in a series of tweets that they are looking for one suspect in the shootings.