WHITE PLAINS — Federal correction officers found an illicit cellular phone in the cell of an ex-cop charged with killing four Middletown men, according to federal court documents.

Nicholas Tartaglione, 51, a former Briarcliff Manor police officer who lived on Old Mountain Road near Otisville, faces 17 federal counts, including four counts of murder in furtherance of a narcotics conspiracy. Federal prosecutors are seeking the death penalty.

The charges stem from the April 2016 deaths of Martin Santos-Luna, 41; his nephews Urbano Morales-Santiago, 35, and Miguel Sosa-Luna, 25; and friend Hector Gutierrez, 32. Prosecutors say that Tartaglione believed that Santos-Luna had taken money meant for a large cocaine deal, and that Tartaglione and others lured Santos-Luna to the Likquid Lounge in Chester, where he was killed. Prosecutors say that Sosa-Luna, Morales-Santiago and Gutierrez were innocent bystanders with no knowledge of the drugs, and that they were taken to Tartaglione’s property near Otisville and killed.

According to a letter prosecutors filed on Monday, corrections staff at the New York Metropolitan Correctional Center in Manhattan saw Tartaglione holding a mini cellular phone in his hand on July 3 while in his cell. Tartaglione told staff that his cellmate had tossed the phone to him as the officers approached. Federal prosecutors said they intend to seek a search warrant to examine the phone’s contents, and have the Bureau of Prisons to transfer the phone to FBI custody. They said they need clarification on whether Tartaglione still contests ownership of the mini-phone, which may only be capable of making voice calls.

Tartaglione lawyers Bruce Barket, Aida Leisenring, Anthony Ricco and Bruce Koffsky wrote a letter Friday to federal Judge Kenneth Karas, saying there could be privileged material in communications stored on the phone. They asked the judge to require not just a search warrant, but also to designate a “filter team” or “taint team,” members of the U.S. Attorney’s Office, to isolate potentially privileged information from the trial prosecutors until the judge rules on the issue.

Barket said Monday that the defense team is not conceding that the phone belonged to Tartaglione, but filed the request as a precaution to protect his rights.

Tartaglione’s case was in White Plains federal court on Monday for a conference, unrelated to the phone issue. His next conference is Aug. 21.

Tartaglione’s codefendant, Joseph Biggs, 57, of Spring Valley, faces the same charges, but there has been little public action on his case.

hyakin@th-record.com