Prosecutors in St. John the Baptist Parish have refused first-degree murder charges against a Reserve man who said he was falsely implicated in a grisly shooting in LaPlace that claimed the lives of two cousins.

Derrence J. Greenup, 29, remains behind bars on unrelated weapons charges, and he also remains wanted by New Orleans police on a count of illegal carrying of a firearm. But court filings show the 40th Judicial District Attorney’s Office opted not to prosecute him in the Oct. 5 slayings “pending further investigation,” according to the Clerk of Court’s Office.

Sheriff Mike Tregre and District Attorney Bridget Dinvaut did not return messages Thursday seeking comment on the case.

Defense attorney David Belfield said authorities apparently accepted that Greenup was at Harrah’s New Orleans Casino at the time of the killings — an alibi Belfield said was supported by video surveillance footage. He said a number of witnesses also vouched for Greenup, who earlier that night had gone to the Saints game and watched them defeat the Dallas Cowboys in overtime.

“Everything he gave the police checked out,” Belfield said. “They know he didn’t do that murder.”

Belfield last year accused the Sheriff’s Office of making a hasty arrest in the case weeks before Tregre faced three challengers in the November election. The sheriff, who eventually cruised to victory in a runoff, refused at the time to comment on Greenup’s alibi and also would not release any details about the evidence his deputies cited in securing an arrest warrant.

Belfield said he managed to obtain a copy of a search warrant that showed a surviving victim of the shooting had identified Greenup as the killer. Detectives apparently interviewed that victim, 23-year-old Damarius Carter, as he recovered at the hospital.

The shooting, which claimed the lives of Sierra and Travis Gregoire, happened before 2 a.m. outside a residence on State Street.

Arriving deputies found Travis Gregoire, 23, in the passenger seat of a vehicle that had struck a mailbox. He was suffering from gunshot wounds to his body and died later that morning at River Parishes Hospital.

Sierra Gregoire, 18, was found still conscious, lying on her side near the front door of a home. She told investigators her assailants had been in a “big white truck” that pulled up next to her cousin’s vehicle and opened fire. She died later that day at University Medical Center.

The third victim, Carter, was driven to the hospital by a neighbor who heard the barrage of gunshots.

While authorities have been tight-lipped about the shooting, they said they are looking for at least three people believed to have been in a white pickup that was found on fire in Reserve the day after the shooting.

Belfield acknowledged that investigators later found the “murder weapon” — an assault-style rifle forensically linked to the shooting — in the attic of Greenup’s residence. But he said Greenup maintains he “never touched” the weapon and that other people had access to it.

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