(JTA) — A federal appeals court overturned the conviction on corruption charges of former New York State Assembly Speaker Sheldon Silver, saying the jury was improperly instructed on the legal aspects of the case.

In overturning the conviction Thursday, the Manhattan court cited a U.S. Supreme Court ruling last year in the case of Bob McDonnell, a former Republican governor of Virginia, that narrowed the definition of the kind of official conduct that can serve as the basis of a corruption prosecution. The conviction of McDonnell also was thrown out.

The Silver case was returned to the original trial court, where the ex-lawmaker, now 73, can be retried, The New York Times reported.

Evidence presented at his first trial showed that he received nearly $4 million in illicit payments in return for taking official actions that benefited others.

Silver, who for two decades was among the most powerful politicians in New York, was convicted in November 2015 of charges including honest services fraud, money laundering and extortion.

In May 2016, a Manhattan federal court sentenced him to 12 years in prison for corruption. The court also ordered Silver to pay a $1.75 million fine and relinquish $5.4 million that he had earned from his schemes.

Silver, who was prominent in Orthodox Jewish circles in Manhattan’s Lower East Side, was convicted in a scheme involving Dr. Robert Taub, an acquaintance who agreed to refer patients to Silver’s law firm. The deal netted Silver over $3 million in referral fees and injury claims. In return, he gave Taub $500,000 in taxpayer funds for research projects, according to prosecutors.

Another scheme involved charges that Silver received $700,000 in referral fees from a real estate firm seen as illegal kickbacks by prosecutors.