Almost anyone can operate a Medicare-licensed equipment-supply company -- even a convicted murderer.

Guillermo Denis Gonzalez, who pleaded guilty to second-degree murder in 1992 and was released from prison in 2004, bought a Medicare-licensed equipment business in Miami two years later. He even notified the federal healthcare program that he was the new owner and president of DG Medical Equipment in December 2006.

On Friday, the Hialeah man pleaded guilty in federal court to one count of defrauding Medicare by submitting $586,953 in false claims for air mattresses, humidifiers and other supplies that were never provided to patients during 2007.

Gonzalez, a 65-year-old Cuban immigrant with a seventh-grade education, faces two to three years in prison on the fraud conviction. But he has much bigger problems: Now he heads over to state court to be prosecuted again -- on a first-degree murder charge accusing him of dismembering a man last year.

Gonzalez is a glaring example of Medicare's lax oversight of Medicare operators in South Florida. The agency claims it regularly conducts criminal background checks on Medicare operators and disqualifies convicted felons, but it didn't flag Gonzalez.

OVERSIGHT PROCESS

An agency spokesman said Friday that DG Medical applied to be a Medicare supplier in the fall of 2006 but that Gonzalez was not listed on the original application.

Spokesman Peter Ashkenaz said questions arose about the equipment provider in February 2007 -- after Gonzalez bought the firm -- and its supplier license was revoked in July of that year because it didn't respond to requests for additional information.

Ashkenaz did not explain why the agency did not perform a criminal background check on Gonzalez.

Even had Gonzalez responded to Medicare's questions, however, disclosure of his criminal history wouldn't have precluded his being licensed, Ashkenaz said.

Medicare can only deny applicants with a felony background if their conviction is 10 years old or less, he said.

``Because his conviction was dated back to 1992 . . . [Medicare] would not have been able to deny his application because he had passed that 10-year limit,'' Ashkenaz said.

``Enhanced enrollment scrutiny is a key goal of Medicare's increased oversight efforts, particularly with respect to [equipment] suppliers,'' he added.

In September 2007, Gonzalez dissolved his medical equipment business, according to state records. The following year, he was charged with the slaying of Sergio I. Quintero, 58, of Hollywood in an argument over money.

THE MURDER

Quintero was at Gonzalez's Hialeah home sitting in his kitchen when the convict ``became enraged'' and punched the jeweler, according to police records. Gonzalez dismembered Quintero while ``periodically'' crushing the corpse's face with a mallet, the arrest report said.

Someone digging through trash found Quintero's left leg in a commercial trash bin in a warehouse alley. The rest of his body parts were found in six black garbage bags in three dumpsters on Hialeah's east side, police said.

Back in 1991, Gonzalez was charged with first-degree murder in the slaying of Eduardo Oses, who was shot to death with a silencer-equipped gun during a money dispute at a Hialeah Tire Kingdom. Gonzalez pleaded guilty to second-degree murder in 1992 and agreed to spend 30 years in prison. He served about 14 years.

After his release, he bought DG Medical for $18,000 in December 2006. The Miami company had already obtained a Medicare supplier license in September of that year, according to court records.

On Dec. 22, 2006, Gonzalez filled out a Medicare form indicating he was the new owner and president of the company.

In 2007, Gonzalez misappropriated physicians' names for prescriptions and Medicare patients' numbers, said assistant U.S. attorney Christopher Clark.

``He illegally obtained'' money from Medicare, Clark said in court Friday.

Medicare, a healthcare program for the elderly funded with taxpayer dollars, reimbursed Gonzalez's business $31,442 -- chump change by healthcare fraud standards in Miami-Dade.

Miami Herald staff writer David Ovalle contributed to this report.