Sublett’s body was found floating in the Frederica River Tuesday morning. He had been shot in the head but had died from drowning.
Investigators said his hands were bound in front of him.
Chief Matt Doering said Friday the reward is coming from the department’s seized assets account. County Commission Chairman Richard Strickland said the county will likely add money to the reward.
A nine-member Georgia State Patrol dive team worked the Frederica River Friday searching for evidence on the muddy bottom.
Mike McDaniel, special agent in charge of the Georgia Bureau of Investigation’s Kingsland office, said new evidence had been taken to the GBI crime lab in Savannah.
Doering said from the beginning the case is being investigated as a homicide, and McDaniel said that is precisely how the GBI is handling it.
The medical examiner still has not determined whether Sublett’s death was a homicide.
Although no one has been arrested in the killing, Commissioner Clyde Taylor said that does not change his advice that people should go about their regular business.
Taylor said none of the information he has been given in private briefings had led him to believe that anyone in the general public is at risk.
“I just don’t see a threat,’’ he said.
Taylor lives in the same St. Simons Island subdivision as did Sublett, and he said that means he likely got all the same complaints from island residents.
There never have been any calls that could be deemed threatening, Taylor said.
“I’m not concerned. I’m going to carry on as normal,’’ he said.
Sublett’s funeral was Saturday at St. Marks Episcopal Church in downtown Brunswick.