iStock/niratBy: MEREDITH DELISO, ABC News

(NEW YORK) — For years, Roy Den Hollander railed against what he saw as an infringement of men’s rights by feminists. A self-proclaimed anti-feminist lawyer, he took on cases against feminist causes, such as “ladies’ night” and women’s studies college classes. His websites host hundreds of pages of openly misogynistic writings.

In those screeds, the court seemed to be the target of much of his ire, saying the justice system “stepped on my rights” and was biased against men.

In a document on his website, Den Hollander wrote disparagingly of several female judges, including Esther Salas, the first Latina to serve on the federal bench in New Jersey, who had presided over one of his cases.

Salas appears to have been the target, investigators said, when, on July 20, Den Hollander opened fire at her New Jersey home, killing her 20-year-old son and critically injuring her husband. Salas was in the basement at the time and was unharmed.

The next day, Den Hollander, 72, the only suspect named in the case so far, was found dead by police in an apparent suicide, according to investigators.

The tragedy highlights a surge in threats to federal judges and their families, and experts say that being a woman and being a minority only make matters worse.

While judges — male and female — face threats for a variety of reasons, the courts have in recent decades become a venue where advocates of so-called men’s rights activism have taken root. The movement, which primarily argues that men are discriminated against in areas such as the government and justice system, has been criticized for the hateful messaging or violence of extreme adherents, like Den Hollander.

And experts say that not only women, but the men connected to them, face danger from this misogyny.

According to the U.S. Marshals Service, there were 4,449 threats and inappropriate communications against federal judges, prosecutors and court officials in 2019. In 2015, that number was 926. Over that same period, the number of threats investigated rose from 305 to 373, peaking at 531 in 2018. The U.S. Marshals Service does not break down this data by gender.

Deadly attacks on federal judges are relatively rare and have primarily involved men, who, according to the Center for American Progress, make up the majority of the seats. Among the handful or so who have been killed was Arizona federal judge John Roll, one of six people who died in the 2011 shooting massacre targeting U.S. Rep. Gabrielle Giffords.

In 2005, Illinois federal judge Joan Humphrey Lefkow lost her husband and mother in a targeted attack at her Chicago home.

Julie Kocurek, the first female criminal district judge in Travis County, survived an attempted assassination outside her home in Austin in 2015, according to the Austin American-Statesman.

According to the New York Times, investigators found a list in Den Hollander’s rental car with the names of three other female judges on it, one of them — like Salas — is also a federal judge. Another was New York Chief Judge Janet DiFiore, her spokesman had previously confirmed to ABC News. The third was a state judge who had presided over one of Den Hollander’s cases, the Times reported.

“Being a federal judge in general is a role that can make enemies. People can be pretty upset about your decisions,” Emily Martin, vice president of education and workplace justice for the National Women’s Law Center, told ABC News. “When you layer that with the fact that if you are a woman, if you are a person of color, there’s a deeper vein of hostility and hatred that those reactions can tap into.”

The attack on Salas’ family “reminds us that there are people who want to kill us solely because of our gender, the color of our skin, our ethnic background — or just because we are different,” Hispanic National Bar Association National President Irene Oria said in a statement last week when the suspected gunman’s racist, misogynistic writings came to light.

That the July 20 attack targeted someone in the legal sector was “not a surprise” to Lecia Brooks, chief of staff for the Southern Poverty Law Center, which monitors hate groups and other extremists, including male supremacists.

The suspect “had an ill-conceived belief that women controlled the legal system,” Brooks told ABC News. “He felt like women who controlled the legal system were able to grant greater leniency and rights upon women. He had this whole warped belief about what was true.”

Den Hollander had “adopted” victimization language common among so-called men’s rights activists, Martin said, “to try to position men as somehow being harmed and victimized by women’s equality.”

The court is one area where men’s rights activism has played out, particularly in child custody cases, Brooks said.

“Around the 1980s it began gaining traction with men who were disgruntled by the results of their experiences with family court,” Brooks said. “It was at that time that no-fault divorce laws began to crop up, and they felt like child custody rulings were discriminating against them.”

Over the years, domestic violence charges have been another area of pushback, Brooks said.

Of late, higher education has been a focus of men’s rights activists, particularly regarding students’ due process rights in disciplining cases of sexual harassment and sexual assault on college campuses, Martin said.

The National Women’s Law Center is behind one of four lawsuits against the Department of Education’s controversial new Title IX sexual harassment regulations, which address due process. One of the changes will allow those accused of sexual harassment or assault to cross-examine their accusers. In its claim, the National Women’s Law Center argues that the regulations, scheduled to take effect on Aug. 14, favor those accused of sexual misconduct and make the process “more intimidating and traumatizing for victims.”

Brooks, another critic of the guidelines, finds that they play “into the hand of this male victimhood narrative.”

In acts of violence where suspects have demonstrated extreme misogyny, women aren’t necessarily the only victims. In addition to Salas’ son, Daniel Anderl, the FBI has tied Den Hollander to the murder in California earlier this month of men’s rights attorney Marc Angelucci.

That aspect of this case reminded Kate Manne, an associate philosophy professor at Cornell University and author of the forthcoming book “Entitled: How Male Privilege Hurts Women,” of another shooting. In 2014, 22-year-old Elliot Rodger killed six people and injured more than a dozen others near the University of California, Santa Barbara. Rodger left behind misogynistic rants that included a video where he vowed “retribution” for women rejecting him. Those murdered included four men.

The cases, Manne told ABC News, showed how “misogyny can really distort someone’s worldview so that they’re a danger to pretty much anyone.”

ABC News’ Aaron Katersky contributed to this report.

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