On June 25, 2010, the New York Times revealed that the FBI and the U.S. Attorney's Office in Brooklyn were investigating Kruger for allegedly seeking campaign contributions in exchange for political favors. On March 9, 2011, Kruger was indicted on charges of bribery and profiting from a hospital merger he supported.
On Thursday, March 10, 2011, Kruger was among eight individuals (including another State legislator) who "surrendered to face charges in a federal corruption case accusing the lawmakers of taking bribes over the course of a decade in schemes large and small." According to the New York Times:
Kruger is accused of “receiving a stream of bribes totaling at least $1 million in exchange for taking official actions.” Among the charges in the complaint is that he shared fees paid to the lobbyist, Richard Lipsky, and then took “the very official acts in favor of which Lipsky had been paid to lobby." . . . [T]he detailed 53-page complaint portrays Senator Kruger as a lawmaker who offered a full range of corrupt services in exchange for bribe payments, performing official acts that included sponsoring and supporting legislation, lobbying other elected officials and directing state monies for the benefit of Mr. Lipsky and the lobbyist’s clients.
Chosen in a special election in 1994, Kruger is a former Ranking Minority member on the Senate Committee on Aging as well as a member of the Crime Victims, Crime and Corrections, Energy and Telecommunications committees, among other standing committee assignments.
Representing what is New York's single largest Russian-American community, Kruger publishes what is purportedly the only Russian-language newsletter printed by elected officials within New York City. Kruger also hosts a weekly program on the Brooklyn Community Access Television (BCAT) channel called Brooklyn Beat, which discusses topical issues related to the borough of Brooklyn.
Prior to his election to the New York State Senate, Kruger was the Assistant Director of Member Services for the New York State Assembly for a decade, as well as the Chairman of Community Board 18.
Kruger is one of three senators, known as the "Gang of Three", who has threatened to abandon the Democratic majority elected to the New York State Senate on November 4, 2008.
On December 2, 2009, Kruger was one of eight Democrats to vote against same-sex marriage legislation.