Angel Nieves Díaz (August 31, 1951 – December 13, 2006) was a Puerto Rican convict and a suspected serial killer who was executed by lethal injection by Florida.

[1] Nieves, who had escaped from a prison in Puerto Rico while serving time for murder, was convicted of shooting and killing the manager of a strip club in Florida in 1979.

[4] In July 1978, Nieves killed the director of a drug rehabilitation center, stabbing him 19 times while he was sleeping.

In 1979, Nieves escaped from the Río Piedras State Penitentiary, nearly beating a guard to death in the process.

[6] On December 29, 1979, Nieves and two friends, Angel Toro and another man who was never caught, robbed the Velvet Swing Lounge, a strip club in Florida.

Nieves was also convicted of a state firearm charge, after officials found a loaded 38-caliber Derringer revolver in his cell.

Although Nieves spoke English poorly and Gajus understood no Spanish, the two communicated with hand signals.

Governor Vilá voiced concerns about the fairness of Nieves' trial, the recanted testimony of Gajus, and Toro's life sentence.

[13] A further investigation concluded that there was negligence in the placement of the needles in Nieves Díaz's arms, whereby the needle would have penetrated entirely through the vein, denying the drugs direct entry into the bloodstream and thereby preventing the drugs from directly reaching desired target sites such as the brain and diaphragm.

[14] Rather, the drugs were injected into soft tissue after the needle entered and immediately exited the vein, thereby greatly lengthening the time before death.

[16] However, on July 18, 2007, the new governor, Charlie Crist, lifted the ban by signing a death warrant, authorizing the execution of Mark Dean Schwab.