The two killings on opposite sides of the country were strikingly similar. A gunman showed up at the front door, posing as a delivery man, and opened fire.
One of the victims was Marc Angelucci, 52, a men’s rights lawyer who was killed on July 11 outside his home in San Bernardino County, Calif. Eight days later, a shooter approached the New Jersey home of Esther Salas, a federal judge, killing the judge’s son and leaving her husband seriously injured.
On Wednesday, the F.B.I. office in Newark, N.J., said in a statement that agents had uncovered evidence linking Mr. Angelucci’s murder to Roy Den Hollander, who is also the primary suspect in the shooting at the judge’s home.
The F.B.I. did not publicly say what evidence had been uncovered. But investigators have concluded that the caliber of the weapon used in the California shooting was the same as the one used in the New Jersey shooting, according to a law enforcement official briefed on the matter.
It marked the first time that the authorities had publicly linked the two killings.
Mr. Den Hollander, 72, was found dead in the Catskills in New York on Monday in an apparent suicide, hours after the shooting at Judge Salas’s home. He was a self-described anti-feminist lawyer who wrote thousands of pages in online screeds denouncing women, including female judges.
Mr. Den Hollander’s connection to Judge Salas and Mr. Angelucci revolved around the same case.
In 2015, Mr. Den Hollander brought a legal challenge to the male-only military draft that was assigned to Judge Salas in Newark federal court. Two years earlier, Mr. Angelucci had brought a similar lawsuit in a different jurisdiction.
In February 2019, a federal court in Houston ruled in Mr. Angelucci’s favor.
In his online writings, Mr. Den Hollander was well aware of Mr. Angelucci’s legal victory and complained that Judge Salas was moving too slowly with his lawsuit.
“The only difference in the Texas case was that two guys were the plaintiffs and a white 70-year-old man was the judge,” Mr. Den Hollander wrote. “Just unbelievable, by now we should have been knocking on the U.S. Supreme Court’s door, but lady unluck stuck us with an Obama appointee.”
Judge Salas, 51, was nominated to the court by President Barack Obama in 2010. She is the first Hispanic woman to serve as a federal judge in New Jersey.