With a fatal bullet wound to his stomach, Franklin Randleman Jr., 18, died on the floor of a Big Pine Key trailer before the sun came up on May 22, 2010.
On Friday, the second man accused in that crime admitted guilt and accepted a plea agreement of 25 years in state prison. Monroe County Judge Wayne Miller handed down the sentence.
William M. Dieguez, now 26, was scheduled for a jury trial on a first-degree murder count and related charges beginning Tuesday in Key West.
One of the prosecution witnesses expected to testify against Dieguez was his accomplice in the pre-dawn robbery and slaying of "Junior" Randleman at the Seahorse RV Park.
Dieguez, accused of firing the fatal shot, pleaded to second-degree murder, robbery with a firearm and armed burglary. His 25 years will run concurrently.
A second defendant, former Marathon resident Sean H. Roberts, 22, accepted a 17-year prison sentence after reaching a plea agreement with Monroe County State Attorney's Office prosecutors last May.
"As part of the agreement, [Roberts] agreed to truthfully testify" at Dieguez's trial, prosecutor Val Winter said Friday.
Betty Massey owned the Seahorse trailer that she shared with Randleman, her grandson. Massey told Monroe County Sheriff's Office detectives that two men wearing masks and armed with a handgun woke her up and demanded money in the 2010 crime. The robbers fled when Massey's car alarm went off.
Randleman was found lying on the floor of the trailer. Attempts to save him failed.
Dieguez, then 22, and Roberts, then 17, were arrested in February 2011 after a lengthy investigation. They were identified as the primary suspects three days after the crime, based on information that Roberts outlined the planned robbery to acquaintances before it happened.
Randleman had numerous problems with law, including a 2009 arrest as one of four Keys teenagers charged in a spree of nine car burglaries. Friends said Randleman had been working to turn his life around and helped neighbors in the trailer park.
Detectives said Randleman was specifically targeted. There were unconfirmed reports of drug deal gone sour.
While committing a prior car burglary, Roberts reportedly stole the .40-caliber handgun used in the slaying. Roberts pleaded guilty to second-degree murder, armed burglary, theft of a firearm and more. He is scheduled to remain in prison until 2032.
Randleman's murder was one of five Florida Keys homicides investigated by Sheriff's Office detectives in 2010. Only one remains a complete mystery. Henry Allwardt, 70, was shot repeatedly in the bedroom of his apartment on Upper Matecumbe Key in September. 2010.