MIAMI -

The U.S. postal inspector has made two arrests in the fatal shooting of a South Florida mail carrier.

Saubnet Politasse, 23, and Pikerson Mentor, 29, are charged with the murder of a federal government employee while in the course of his duties, carjacking of a postal truck with death resulting, theft of a key for a U.S. Postal Service mail receptacle, use of a firearm in the commission of a crime of violence and conspiracy. Both appeared before Federal Magistrate Judge Jonathan Goodman on Thursday afternoon.

Politasse and Mentor are accused of killing mail carrier Bruce Parton five months ago. Parton, 60, was delivering mail to the Monte Carlo Condominiums on Dec. 6 when he was shot twice. Miami-Dade police said the gunman also stole Parton's postal truck and then abandoned it a short distance away.

According to the criminal complaint, investigators received a tip that a person named Diddy, a person named Gangsta and another person killed Parton in order to steal his mail key so they could use it to steal mail and commit identity theft and tax fraud.

After months of painstaking investigation, including review of surveillance tapes, witness interviews, analysis of driver and vehicle information records, review of Miami-Dade Police Department and other criminal records and analysis of telephone toll records, Diddy was identified as Mentor and Gangsta was identified as Politasse.

On May 4, officers from the North Miami Police Department arrested Politasse, who was accused of driving without a license. According to prosecutors, under the driver?s seat, a police officer discovered a unique looking key, which was later identified as a U.S. postal key with an obliterated serial number.

According to the complaint affidavit, Politasse has admitted to the crime. Mentor was arrested early Thursday morning.

In court on Thursday, prosecutors indicated a third person has also been arrested and is being treated as a witness.

Both Politasse and Mentor have lengthy criminal records and both have served time in state prison for committing violent crimes.

"My sincerest sympathies go out to the Parton family for the cold-blooded killing of their loved one while doing his job," U.S. Attorney Wifredo Ferrer said. "It is my hope that today's charges at least provide them with a sense of closure and hope for justice."

"The protection and safety of our letter carriers is the No. 1 priority of the U.S. Postal Inspection Service," said Henry Gutierrez, of the U.S. Postal Inspection Service. "These arrests represent the relentless effort by the law enforcement community to ensure that those responsible for harming our civil servants are brought to justice."

If convicted, Politasse and Mentor could face up to life in prison.