NORTH BRUNSWICK, New Jersey (WABC) -- The FBI confirmed Wednesday that it has evidence linking the now-deceased suspect in the shooting at a federal judge's home in New Jersey to the murder of another attorney in California.
Roy Den Hollander was found dead of an apparently self-inflicted gunshot wound in Sullivan County, New York, on Monday, the day after investigators say he murdered the 20-year-old son of US District Court Judge Esther Salas and wounded her husband.
The FBI says Hollander is also believed to be responsible for the death of Mark Anglelucci in San Bernardino two weeks ago, with details that are eerily similar: A man dressed in a FedEx uniform knocked on the door and then opened fire.
"As the FBI continues the investigation into the attack at the home of US District Court Judge Esther Salas (District of New Jersey), we are now engaged with the San Bernardino California Sheriff's Office and have evidence linking the murder of Marc Angelucci to FBI Newark subject Roy Den Hollander," FBI Newark said in a statement.
Investigators believe the same .380 Walther semiautomatic handgun was used in both shootings, they're waiting for ballistics to match the bullets.
Authorities say both Hollander and Angelucci worked on a similar, but separate male-only military draft suit and there was long standing competitive animosity between the two.
An investigative theory continues to be that Hollander was terminally ill with cancer and set out to settle outstanding grievances with the murders.
Authorities said Tuesday that Hollander may also have been targeting another female judge after the name and photo of New York State' Chief Judge Janet DiFiore were found in his car.
Also in the car was an envelope addressed to Judge Salas, though there is no word on what is inside the envelope.
Judge Salas' 20-year-old son Daniel Anderl was shot multiple times and died at their home, while her husband -- criminal defense Attorney Mark Anderl -- is in critical but stable condition at the hospital after undergoing surgery.
Hollander's body was discovered in a car by a municipal employee in the town of Liberty.
Investigators believe he might've been seeking revenge after appearing before judge Salas in 2015. He was also recently diagnosed with terminal cancer. A GoFundMe page for Hollander was recently deactivated.
Police said Hollander was wearing a face covering and a FedEx uniform, posing as a delivery driver when he arrived at the family home around 5 p.m. Sunday. Authorities say Daniel Anderl opened the door and was immediately shot, with the gunman then wounding Mark Anderl before fleeing the scene.
There was no FedEx truck involved, and the suspect used an ordinary car to make a getaway, sources said.
In the 2015 case before Judge Salas, Hollander represented a woman who wanted to register for the military draft. He was replaced last June as the woman's lawyer before the case was fully resolved.
The court docket did not indicate a reason for his replacement, and the woman's current attorney could not be reached.
Hollander has sued Manhattan nightclubs for favoring women by offering ladies' night discounts and sued the federal government over a law that protects women from violence. He has also sued Columbia University for offering women's studies courses, accusing the school of using government aid to teach a "religionist belief system called feminism."
In 2017, he wrote a letter to then-Attorney General Jeff Sessions in which he complained of living under "Feminazi" rule. He also appeared on ABC News, arguing that Ladies' Nights were unfair.
Judge Salas has received threats in the past, sources say, and she is now receiving 24-hour protection from the US Marshals.
The Associated Press contributed to this report.
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