Daniel Pelosi was arraigned before state Supreme Court Justice Robert W. Doyle on the second-degree murder charge and then held without bail. He had surrendered hours earlier in the company of three lawyers.
He did not speak at the arraignment, but attorney Gerald Shargel entered a plea of innocent on his behalf. He faces 25 years to life in prison if convicted.
Pelosi, 40, became the focus of tabloid headlines - and a grand jury probe - after he married widow Generosa Ammon in January 2002. The couple later split and she has since died of cancer.
Ammon and her multimillionaire husband, Theodore Ammon, were just days away from finalizing a nasty divorce when he was killed in his sprawling East Hampton mansion in October 2001. An autopsy showed he was smashed in the head with a blunt object.
Generosa Ammon married Pelosi in January 2002. The estate was worth a reported $100 million.
Pelosi, who has a record of drunken driving arrests and other skirmishes with law enforcement, has repeatedly proclaimed his innocence in Ammon's death.
Generosa Ammon died in August at age 46. Pelosi received a reported $2 million post-nuptial payment, but nothing in her will. Pelosi's attorneys are challenging the validity of the will in court, and Ammon's sister is fighting for custody of her two children.
In court papers released last August, Doyle said that a suspect in the killing owned a laptop computer that was used to access a security system in Ammon's mansion on the weekend of the death.
While Doyle did not name Pelosi, he wrote, "the individual who is a target of this investigation married the widow of the murder victim."
Theodore Ammon, 52, ran the private equity firm Chancery Lane Capital and was chairman of Jazz at Lincoln Center, a Manhattan concert series. He also was a former general partner at the investment firm Kohlberg Kravis Roberts & Co.
By Frank Eltman