MIAMI -- After years on death row, Joseph Ramirez is back in a Miami-Dade courtroom for a fourth trial on murder charges for a crime he allegedly committed nearly 24 years ago.

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NBC6's Nick Bogert was at the courthouse Thursday where the trial began.

Ramirez is accused in the 1983 Christmas Eve slaying of 27-year-old Mary Jane Quinn. The night courier's body was discovered in a FedEx building near Miami International Airport.

"She was brutally beaten," prosecutor Flora Seff told jurors for a fourth time. "He knew that there was money in the mailbag."

Police said Quinn died of multiple stab wounds to her body and blunt trauma to her head. Additional injuries found on her body included cuts on her hands and back and one stab wound into her chest cartilage.

At the scene, police said they found blood spatters and pools throughout the dispatch area and break room indicative of a struggle.

"It is extremely difficult to listen to how she was murdered," Lynn Minick, Quinn's sister-in-law, said.

"He's been able to outlast the system," Quinn's brother, Bill Minick, said.

A hair was in the palm of Quinn's hand, and experts compared hair samples taken from Ramirez with that hair and determined that it did not belong to Ramirez.

"He could not have committed this crime," Ed O'Donnell Jr., Ramirez's defense attorney, said. "This hair is not Joseph Ramirez's hair."

O'Donnell argued that Ramirez was a scapegoat for police who were desperately in need of solving the high-profile crime, and he cited the hair found on Quinn as a prime example.

Ramirez's first three trials were scuffled by the Florida Supreme Court because it said improper testimony was taken about the alleged murder weapon.

"Underneath the passenger's seat -- hidden from view unless you looked there -- was a large butcher knife," Seff told the jury.

But now the defense said DNA tests on that knife show no trace of Quinn's blood.

They claim other blood evidence at the scene points to someone else.

Three other juries have found Ramirez guilty of murdering Quinn, but her family members said they are worried that the case has deteriorated.

"Some of the major witnesses are either incapacitated or dead," Bill Minick said.

A friend of Quinn's, Nancy Vanderplate, said, "This has killed her whole family with all these memories. We think he is very dangerous and shows not remittance or remorse."

Ramirez has spent 23 years in jail, police said, and 17 of those on death row.

His attorney claims an innocent man has spent most of his life in jail.

Quinn's family members said it is hard for them to know that Ramirez does not face the death penalty in his fourth trial.

"He is now guaranteed to live when he shouldn't," Bill Minick said. "My sister didn't live."

Police said they found Ramirez's bloody fingerprint on a doorjamb near the victim's body, and his attorney confirms that it is his fingerprint but said it is also his blood because he injured himself a week earlier while performing his janitorial duties onsite.

Ramirez worked for an independent janitorial company, which serviced the FedEx offices.

With that fingerprint identification, Ramirez was arrested and charged with first-degree murder.

Police said Ramirez had cleaned the FedEx office on the afternoon of Dec. 24, 1983.