Updated at 2:50pm.

Just when you thought New York politics couldn't get any more drenched into dirty money, Bronx Assemblyman Eric Stevenson was charged on Thursday morning with several counts of corruption and conspiracy, stemming from a series of bribes Stevenson allegedly sought in exchange for writing and supporting legislation that would help certain businesses in Stevenson's district. The U.S. Attorney's Office in the Southern District of New York brought the charges against Stevenson and four other men participating in the bribery scheme.

According to a copy of the complaint, Stevenson solicited bribes, totaling approximately $20,000, from those four — Igor Belyansky, Rostislav Belansky, Igor Tsimerman, and David Binman — in exchange for legislation that would benefit a chain of adult day care centers that the four men were hoping to erect in various locations around the Bronx. (Stevenson serves 79th Assembly District, which comprises portions of south-central Bronx.) The complaint, which arose from a complex surveillance operation that tracked Stevenson and the four men as they spoke and exchanged envelopes full of cash on multiple occasions, says that Stevenson agreed to introduce and write legislation that would halt all new construction on adult day care centers in New York City for three years, thus limiting any competition to his friends' new venture.

The arrest of Stevenson, who was elected in 2010, is the latest episode in a bad week for New York politics. On Tuesday, FBI officials arrested State Sentator Malcolm Smith and New York City Councilman Dan Halloran for allegedly attempting to bribe several county officials into approving Smith's run for mayor of New York City, a race with no lack of political drama already.

It's probably won't be the last episode, either. The criminal complaint against Stevenson indicates that the U.S. Attorney's Office cooperated with another assemblyman in investigating and prosecuting him, on one condition: that, upon Stevenson's arrest, the (currently unnamed) assemblyman would resign from office. Who might that be? According to the New York politics blog Politicker, the scant details offered in the complaint suggest that Assemblyman Nelson Castro, who represents a portion of the Jerome Avenue thoroughfare (where one of the adult day care centers in question is located) may be the secret assemblyman. Castro's office refused to speak to Politicker until the end of the day, however, so it's safe to say that Stevenson won't be the only one in the news today.

Update, 2:50pm: Bronx Assemblyman Nelson Castro has admitted to cooperating with the U.S. Attorney's Office in investigating his colleague Eric Stevenson for corruption. As part of his deal with the office, Castro will resign on Monday. But that's not all! According to the full statement released by his office on Thursday afternoon, Castro has served as an informant for city and state investigators for nearly four years, ever since he was indicted by a grand jury for perjury in 2009, and decided to clean up his act. (Castro was elected to his current office in 2008.) In the same statement, Castro says he will "continue to cooperate with State and Federal authorities in this prosecution and in other investigations."