Suffolk GOP picks Ray Tierney to challenge county DA Tim Sini

Raymond Tierney, a former federal and Suffolk County prosecutor who spearheaded high-profile government corruption and MS-13 gang cases, is the Republican nominee to challenge Suffolk County District Attorney Tim Sini in November, officials said Thursday.

Tierney, 55, who is not enrolled in a political party, also is the Conservative Party nominee.

Sini, a Democrat, took office in 2018.

Tierney, of Holtsville, announced his candidacy Thursday outside the Alfonse M. D'Amato U.S. Courthouse in Central Islip. Tierney was surrounded by about a dozen retired law enforcement officers and relatives of MS-13 murder victims, whose killings he prosecuted.

Tierney said he was running "to ensure the office works every day to prosecute crimes fairly, without fear, without favor and all in order to ensure the health, safety and welfare of all Suffolk County residents — not just the politically connected and the political donor class."

Tierney, who recently became Suffolk Off Track Betting Corp.'s chief counsel for compliance and enforcement, said his experience as a prosecutor makes him "uniquely qualified" to become district attorney.

As an assistant U.S. attorney, Tierney in 2018 prosecuted corruption cases against former Nassau County Executive Edward Mangano, his wife, Linda, and former Oyster Bay Supervisor John Venditto. Venditto was acquitted of all charges, but the jury deadlocked over charges against the Manganos.

In 2019, Edward Mangano was convicted of conspiracy to commit federal program bribery, federal program bribery, conspiracy to commit honest services wire fraud, honest services wire fraud and conspiracy to obstruct justice.

Linda Mangano was convicted of conspiracy to obstruct justice, obstruction of justice and two counts of lying to the FBI.

Venditto later pleaded guilty to a single corruption charge in state court.

Tierney helped prosecute former Suffolk Conservative Party leader Edward Walsh in 2016. Walsh was convicted of pocketing hundreds of thousands of dollars in pay from the Suffolk sheriff’s department while golfing, gambling and politicking on county time.

Tierney also prosecuted MS-13 gang members, including Rene Mendez Mejia, Adalberto Ariel Guzman and Juan Garcia, who were convicted in 2010 of murdering Vanessa Argueta, 19, and her 2-year-old son Diego Torres in Central Islip.

"Thanks to Ray Tierney, countless rapists, murderers and other criminals are off the streets and behind bars where they belong," Suffolk GOP chairman Jesse Garcia said in a statement.

Sini served as Suffolk County police commissioner before his election as district attorney.

"Suffolk voters know that DA Sini’s record of protecting our families by keeping violent and dangerous offenders off our streets is unmatched," county Democratic chairman Rich Schaffer said in a statement.

Tierney, a graduate of Brown University and St John’s University School of Law , first worked as a Suffolk assistant Suffolk County district attorney from 1992 to 1999.

He then spent two years at the law firm Shaub, Ahmuty, Citrin & Spratt LLP before returning to the Suffolk district attorney's office, where he served from 2002 to 2008.

Tierney became an assistant U.S. attorney in the criminal division of the U.S. Attorney’s Office in the Eastern District in 2008, remaining until 2019.

Tierney then worked as an executive assistant district attorney for the Kings County district attorney in Brooklyn, where he oversaw the violent criminal enterprises bureau, crime strategies unit and the body worn camera unit until his departure in February.

By Rachelle Blidner

rachelle.blidner@newsday.com@rachelleblidner

Rachelle Blidner covers Suffolk County government, politics and breaking news.