PATERSON — A man serving four back-to-back life sentences for the cold-blooded slaying of four people at an underground gambling club financed by the FBI has lost another appeal.

David Baylor, now 36, was convicted in 2008 of shooting four victims, pumping a single bullet into each of their heads, during a robbery on Dec. 14, 2005.

The after-hours club in this city was secretly being kept open by federal investigators who wanted to use it to attract gang members they were investigating.

One of Baylor’s victim’s pleaded for her life before he pulled the trigger — and Baylor later joked about the massacre, according to an accomplice who testified against him.

Baylor has already lost previous appeals of the verdict and sentencing, which puts him away for four consecutive life sentences for the murders, plus another 10 years on top of that for a gun charge. The state Supreme Court has declined to take up his case.

In 2012, Baylor filed a petition for post-conviction relief arguing that both his trial and appeal attorneys were ineffective. But the courts rejected his arguments. He appealed that ruling and was rejected once again by a panel of appellate judges this week, who said his “petitions and submissions are devoid of any facts.”

And even if the attorneys were ineffective, the judges add that Baylor “made no showing that additional investigation, including interviewing witnesses or inspecting the crime scene, would have yielded evidence or testimony that would have affected the outcome of the trial."

The man convicted of holding up the gambling club with Baylor, Hamid Shabazz, was sentenced in 2012 to a combined 22 years in prison. He already was serving 23 years for an unrelated drug-dealing and robbery case. A Superior Court in Passaic County also sentenced Shabazz to an additional six months in prison for refusing to testify against Baylor at trial.

Sergio Bichao is deputy digital editor at New Jersey 101.5. Send him news tips: Call 609-438-1015 or email Follow on Twitter and Facebook