On April 18, 2026, the Clay County Sheriff’s Office marked a grim anniversary by renewing its public appeal in the unsolved 2009 killing of Mark Gregg in Green Cove Springs. Gregg, 54 at the time, was a disabled truck driver who was found shot multiple times inside the couple’s North Road home on April 18, 2009, after his wife discovered him. Detectives say they collected forensic evidence at the scene and noted that one firearm from the household was missing, and they are now asking residents to dig into old memories and share any tip that might finally move the case.
In a Facebook reel posted April 18, the Clay County Sheriff’s Office recaps what is known and urges anyone with information to speak up. The post lists Detective Sean Holmes as the contact on the case, and it points residents to the SaferWatch app and to First Coast Crime Stoppers for anonymous tips. The message leans hard on the idea that even something that seems minor could matter, and the reel includes a short case summary along with direct contact details for the investigator handling the file.
Case Details And The Missing “Street Sweeper”
Records compiled by Project Cold Case state that Gregg was found around 9 p.m. on April 18, 2009, having been shot multiple times at close range inside his North Road residence. Investigators reported that a jewelry box near the bed appeared to have been rummaged through and that cigarettes were missing, yet there were no obvious signs of forced entry. Authorities believe an Armsel Striker 12-gauge shotgun, a revolving-cylinder weapon often described as a “street sweeper,” was taken from Gregg’s collection and may be the murder weapon. Project Cold Case notes that the Striker seemed to be the only firearm unaccounted for from the home.
Investigative Work And Contact Information
Clay County detectives say they conducted extensive interviews and collected forensic evidence during the original investigation, but no arrests have been made. The sheriff’s reel shares direct contact information for the lead investigator and lists Detective Sean Holmes’ email and phone number for anyone willing to come forward. For those who prefer to call a general line, the Clay County Sheriff’s Office lists (904) 264-6512 as its non-emergency number on the agency’s contact page.
How To Submit Tips
Anyone who recalls conversations, unusual vehicles, or visitors in the North Road neighborhood in April 2009 is encouraged to pass that along, anonymously if needed. Tips can be sent through the SaferWatch app or by calling First Coast Crime Stoppers at 1-866-845-8477. Project Cold Case also repeats the Crime Stoppers tip line and reward information in its entry on Gregg’s case. Detectives say that even a small recollection could help revive old leads.
Why Renewed Attention Can Matter
Cold cases sometimes move when new witnesses decide to come forward or when forensic tools improve, and national reporting has highlighted how genetic genealogy and DNA advances have reopened many long-unsolved investigations. For background on that trend, see coverage from CBS News. Clay County investigators say they hope this fresh push on the anniversary of Gregg’s killing will bring in the kind of tip that can finally break the case.
