Following the revelation earlier this morning that he had helped federal prosecutors build a bribery case against colleague Eric Stevenson, Bronx Assemblyman Nelson Castro said he will resign from office effective Monday, April 8, in a statement released through his attorney.

It’s still unclear exactly why Castro resigned, but his statement left a few clues.

In the statement, he said that he was indicted by the Bronx District Attorney’s office in the summer of 2009 on perjury charges related to “a civil matter” that cropped up during his campaign for assembly back in 2008.

After that indictment, Castro said he agreed to cooperate with the Bronx DA and, later, the U.S. Attorney’s Office for the Southern District of New York, which filed the charges against Stevenson.

The “civil matter” Castro is most likely referring to stems from accusations that Castro committed voter fraud during his 2008 campaign. That summer, it was discovered that nine people were using his one-bedroom apartment as their registered voting address and that 15 people were using his campaign manager’s district address.

During a hearing on the matter, Castro said he didn’t know the people who had used his address, although, according to the Daily News, some of them were his relatives. A Bronx judge, however, ultimately allowed Castro to stay on the ballot and he won. He won re-election in 2010 and 2012.

According to the criminal complaint against Stevenson, Castro began cooperating with the federal bribery investigation in January 2012 and worked closely with law enforcement officers to build the case against Stevenson and a group of developers. It appears the only money Castro took as part of the scheme was under direction from law enforcement officers.

In essence, Castro’s statement claims his only transgression occurred before he was elected to office, which would exonerate him from involvement in the Stevenson scandal.

“I deeply regret my misconduct while campaigning before I was elected to office,” Castro said in his statement. “It is my sincere hope that my constituents remember me most for the good I have done as their representative, rather than for the poor example I set as a candidate.”

Either way, Castro’s out and a special election will have to be held to find his replacement in the 86th District.

Below is the full text from Castro’s statement:

Today I announce that I am resigning my seat in the New York State Assembly, effective Monday, April 8, 2013.

On July 31, 2009, I was indicted by a Bronx County Grand Jury for committing perjury in a 2008 civil matter, held prior to my election to the Assembly. I appreciate the seriousness of my misconduct.

Thereafter, I agreed to cooperate with the Bronx District Attorney’s Office and, later, the United States Attorney’s Office for the Southern District of New York, in conjunction with various investigations aimed at rooting out public corruption. As one result of this cooperation, among other things, this morning a complaint was unsealed in the U.S. District Court for the Southern District of New York charging Assemblyman Eric Stevenson and four others with various federal crimes. I continue to cooperate with State and Federal authorities in this prosecution and in other investigations.

I am very proud of my accomplishments and the many benefits that I have secured on behalf of my district over the last four years. These include helping thousands of constituents to apply for U.S. citizenship on a no-fee basis, and providing educational programs focusing on the Citizenship & Naturalization Exam; obtaining funding for technology purchases and initiatives for the schools in my district; sponsoring events for senior centers and youth programs in my district and beyond; and securing additional low cost housing units in the area. Most of all, I take pride in how our diverse population has united to transcend racial and ethnic differences and work together.

My district is comprised of hard working and honest people, devoted to their families and to their community. I deeply regret my misconduct while campaigning before I was elected to office. It is my sincere hope that my constituents remember me most for the good I have done as their representative, rather than for the poor example I set as a candidate.

Because of the sensitive nature of ongoing prosecutions and investigations, I must direct all further inquiries to my attorney, Michael C. Farkas, Esq.