(CNN) -- A former police officer convicted of multiple murders in the 1980s was executed Tuesday night in Florida.
Manuel Pardo, 56, was pronounced dead at 7:47 p.m. EST at the Florida State Prison in Starke, according to Ann Howard, spokeswoman with the Florida Department of Corrections.
His last meal consisted of red beans and rice, roasted pork chops, plantains, avocado and tomato slices with olive oil, eggnog and pumpkin pie, she said.
Pardo was sentenced to death after being convicted in 1988 of nine counts of first-degree murder.
His attorneys had argued that Florida's recent change in the drug combination it uses for lethal injections would violate their client's civil rights. A judge denied the complaint.
In another legal filing, the Supreme Court of Florida denied Pardo's argument that he should have never been tried because he was incompetent to stand trial. David Waksman, who prosecuted the case, dismissed the claim, saying, "He was just a cold-blooded killer who used to be a cop."
Pardo's life started on the other side of the law, according to court documents filed by his attorneys. At age 17, he enlisted in the Navy and served honorably from 1974 to 1978. In 1981, Pardo re-enlisted in the Marines and remained a reservist while he worked for the Florida Highway Patrol and the Sweetwater Police Department.
In 1985, Pardo was fired from the police department and left the reserves when, according to court documents, "he falsely testified in court about police corruption in the Bahamas." His attorney said the stress of losing his job, compounded with a serious undiagnosed disease, turned him into "someone he was not," a killer.
During his trial, Pardo took the stand and admitted to the murders. "He came up with this vigilante story," recalls Waksman. "He said, 'I'm ridding the community of this vermin and technically it is not murder because they're not human beings.'"