Hours after shots rang out in a quiet Middlesex County neighborhood on Sunday, leaving the son of U.S. District Judge Esther Salas dead and her husband critically injured, the FBI in Newark circled its nets around a killer.

Were looking for one subject and ask that anyone who thinks they may have relevant information (to) call us, the agency tweeted at 10:51 p.m. On Monday, the FBI identified New York attorney Roy Den Hollander as the gunman and said the suspect is now deceased.

In the two days since the slaying of Daniel Anderl and the shooting of his father, criminal defense attorney Mark Anderl, law enforcement has provided few details about how the shooting occurred and almost nothing as to motive.

Instead, the media has been left on its own to paint a picture of the alleged shooter as a disgruntled attorney and activist who may have been motivated by the misguided notion he was furthering the cause of mens rights.

Here is what we know:

The killing was calculated and occurred in the late afternoon over the weekend

The suspect, dressed as a FedEx delivery driver, arrived at Salas home on Point of Woods Drive about 5 p.m. on Sunday.

Her son, Daniel Anderl, 20, is believed to have answered the door with his father, Mark Anderl, 63, nearby.

When the door opened, the gunman fired multiple shots, striking both Daniel Anderl and his father. Daniel Anderl died at the scene. Mark Anderl is hospitalized in critical but stable condition.

Salas, 51, was in the basement at the time of the shooting and was not injured.

After the shooting, the bogus delivery driver fled in an unknown direction.

Daniel Anderl, 20. (Photo courtesy of Catholic University)

The suspect was identified as Den Hollander, an anti-feminist lawyer who had a case before Salas

A self-described anti-feminist lawyer, Den Hollander was best known for unsuccessful lawsuits challenging the constitutionality of ladies night promotions at bars and nightclubs.

Den Hollander was part of a pending case before Salas regarding the U.S. Militarys male-only draft registration system, court records show.

The lawsuit argues, in part, that requiring only men to register in the draft discriminates against both sexes in violation of Equal Protection as incorporated into the Fifth Amendment of the U.S. Constitution.

In an interview with NJ Advance Media, attorney Nick Gravante said his firm took over the case last year after Den Hollander called him saying he had terminal cancer, and could not continue pursuing it.

Among the other suits Den Hollander filed was a case alleging night clubs in New York City discriminate against men by offering ladies nights discounts.

Now is the time for all good men to fight for their rights before they have no rights left, a passage on his website read. His site also refers to a Lady Judge who decided one of his cases.

In 2017, Den Hollander wrote a letter to then-Attorney General Jeff Sessions in which he complained of living under "Feminazi" rule. His litigation, and willingness to appear on television, earned him spots on ABC News, The Colbert Report and MSNBC.

Another lawsuit argued night clubs were violating human rights by charging men hundreds of dollars for bottle service. In 2008, he unsuccessfully sued Columbia University for providing women's studies classes, saying they were "a bastion of bigotry against men."

The suspected gunman researched Salas and wrote that he did not like Hispanic women judges

Den Hollander wrote in an online essay in 2019 about a planned hearing apparently before Salas, the first Hispanic woman to be appointed to the U.S. District Court in New Jersey. He referred to the jurist as a lazy and incompetent Latina judge appointed by (President Barack) Obama.

In other online ramblings, Den Hollander said he researched Salas background and made racist comments about Hispanic judges. The document was posted on a website with its domain name registered to Den Hollander.

Den Hollander bashed Salas earlier legal career, describing her as working for an ambulance chasing firm and representing neer-do-wells as a federal public defender.

He also criticized Salas for joining politically correct organizations trying to convince America that whites, especially white males, were barbarians, and all those of a darker skin complexion were victims.

Den Hollander claimed his bitter divorce helped fuel his anti-feminist stance

According to his online resume, Den Hollander focused much of his practice on representing men in civil cases, which he referred to as antifeminist cases or guys'-rights cases.

In 2008, he told the New York Times that his bitter divorce years earlier from a woman he married in Russia helped fuel his anger toward feminists. He also said he wanted to fight laws that he believed unfairly favored women.

The same gunman may have been involved in a California shooting with eerie similarities

The New York Times, citing two law enforcement officials, reported the FBI is investigating whether Den Hollander was involved in the July 11 killing of mens rights lawyer Marc Angelucci in San Bernardino, California.

Angelucci was shot at his front door by a gunman wearing a FedEx uniform, according to published reports.

According to the National Coalition For Men, Angelucci took on high profile cases involving paternity fraud and advocated for male victims of domestic violence in California.

Marc AngelucciFacebook

Another prominent judge, a woman serving in New York State, may also have been targeted

The FBI warned court officials in New York that Den Hollander had a photo of that states Chief Judge Janet DiFiore in his car. The photo was found along with Den Hollanders body on Monday in Rockland, New York.

Thats what I understand to be true. At this point, thats all I have, said Lucian Chalfen, director of communications for New York State Courts.

From left, U.S. District Court Judge Esther Salas, Roy Den Hollander and New York State Chief Judge Janet DiFiore.File

Salas was the presiding judge in high-profile cases, including one involving Jeffrey Epstein

Salas has handled cases involving members of the Grape Street Crips, in connection with a long-running drug-trafficking network that was taken down by the FBI in 2015. She was also the judge who sent Real Housewives stars Joe and Teresa Giudice to prison.

In 2017, she barred federal prosecutors from seeking the death penalty against an alleged gang leader charged in several Newark slayings, ruling the mans intellectual disability made him ineligible for capital punishment. Salas later sentenced the man to 45 years in prison.

More recently, Salas has presided over an ongoing lawsuit brought by Deutsche Bank investors who claim the company made false and misleading statements about its anti-money laundering policies and failed to monitor high-risk customers, including Jeffrey Epstein.

FILE - In this Oct. 15, 2014 file photo, Giuseppe "Joe" Giudice, from the television show "Real Housewives of New Jersey," appears in a New Jersey courtroom. (William Perlman/NJ Advance Media via AP, Pool)AP

Den Hollander claimed he had terminal cancer and wrote about revenge

Roy Den Hollander wrote in an online essay last year that he was dying of cancer. A GoFundMe page titled Cancer knocks you down & doctors finish you off has been deactivated.

The New York Post reported that Hollander wrote about revenge fantasies and his cancer diagnosis in an online screed.

Deaths hand is on my left shoulder...nothing in this life matters anymore, he wrote in the manifesto. The only problem with a life lived too long under Feminazi rule is that a man ends up with so many enemies he cant even the score with all of them.

Our journalism needs your support. Please subscribe today to NJ.com.

Anthony G. Attrino may be reached at tattrino@njadvancemedia.com.

Read more:

Everything we know about Roy Den Hollander and the fatal shooting at federal judges house in N.J. - NJ.com