Den Hollander had a gender-equity lawsuit, filed in 2015, that was being heard by Salas involving a young woman who wanted to register for the military draft. He also mentioned the judge in writings posted online, deriding her as a ladder climber who traded on her Hispanic heritage to get ahead.
A package addressed to Salas was found along with Den Hollander's body, the officials said.
In a screed Den Hollander posted online, he also wrote of posing as a FedEx delivery person to speak with a young girl, the same tactic the gunman apparently used at the door to the judge's family home.
Den Hollander was best known in years past for unsuccessful lawsuits challenging the constitutionality of "ladies night" promotions at bars and nightclubs. His litigation, and willingness to appear on television, earned him spots on The Colbert Report and MSNBC.
Daniel Anderl, Salas' son, was set to be heading back shortly to The Catholic University of America in Washington, D.C., where he was named to the Dean's List this northern spring.
"I was shocked last night to hear news of Daniel Anderl's tragic death in New Jersey. Daniel was a rising junior, enrolled for classes beginning in the next few weeks," university President John Garvey wrote on Twitter. "He turned 20 last week."
Esther Salas, seated in Newark, was nominated by President Barack Obama and confirmed in 2011.
Prior to that, she served as a US Magistrate Judge in New Jersey, after working as an assistant public defender for several years.
Salas, born in California to a Cuban immigrant mother and Mexican father, spent most of her childhood in Union City, New Jersey.
After helping her family escape a devastating house fire, she acted as her mother's translator and advocate, foreshadowing her career in law as she argued her family's case to welfare officials, according to a 2018 magazine profile.
In the profile, Salas spoke of her son possibly following his parents into the legal profession.
"He's been arguing with us since he could talk — practicing his advocacy skills," Salas told New Jersey Monthly. "I don't want to dissuade him, but I was pulling for a doctor."
Just last week, Salas was appointed to hear 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 convicted sex offender Jeffrey Epstein.
Her highest-profile case in recent years was the financial fraud case involving husband-and-wife "Real Housewives of New Jersey" reality TV stars Teresa and Joe Giudice, whom Salas sentenced to prison for crimes including bankruptcy fraud and tax evasion. Salas staggered their sentences so that one of them could be available to take care of their four children.
In 2017, she barred federal prosecutors from seeking the death penalty against an alleged gang leader charged in several Newark slayings, ruling the man's intellectual disability made him ineligible for capital punishment. Salas later sentenced the man to 45 years in prison.
- AP