New York Assembly Speaker Sheldon Silver was found guilty of fraud and other charges of corruption on Monday for using his political platform to help a cancer researcher and real estate developers in exchange for $4 million in kickbacks.

A federal court found the 71-year-old Manhattan Democrat guilty of all seven counts of corruption, including fraud, extortion and money laundering, reports NBC New York. He now faces up to 20 years in prison on each of six of the seven counts. A sentencing date has yet to be set.

Following the verdict, Silver's attorney Steven F. Molo said the defense was "obviously disappointed in the verdict, and we intend to file vigorous post-trial motions seeking to set it aside," The New York Times reported.

"We'll take it from there," he added, indicating that they would challenge the verdict.

After leaving the courthouse, Silver, who was first elected to the Assembly in 1976, told reporters that he was "disappointed" in the verdict. "Ultimately I believe after we file the legal challenges we will have a different result," he said.

Silver decided to step down from his 21-year reign as the Assembly Speaker in January just days after he was arrested by federal authorities on charges of corruption and bribery. Federal prosecutors accused him of abusing his political office by accepting bribes and kickbacks worth millions of dollars.

A federal corruption probe was also launched against Silver in 2013, which found that for the last decade he underhandedly accepted about $4 million in payments from a small law firm called Goldberg & Iryami. FBI agents and prosecutors with U.S. Attorney Preet Bharara's office also said that the Democratic official did essentially no work for the payments, nor did he officially disclose the payments.

In a statement, Bharara said that "Sheldon Silver got justice, and at long last, so did the people of New York."