Investigators have found all but one of the weapons used in an armed robbery and slaying at a local grocery store.

“We have recovered everything we were looking for except the guard’s gun,” said Forsyth County Sheriff Ted Paxton.

Paxton said evidence indicates a 9 mm Glock was used in the Sept. 5 killing of 37-year-old David Casto, who was shot while working security at Ingles on Canton Road.

The sheriff said an autopsy revealed that Casto’s death was caused by a 9 mm weapon.

“There was only one 9 mm pistol present and it was his,” Paxton said.

Shortly after four teenagers were arrested for the shooting, the sheriff’s office put up a $2,000 reward for the recovery of weapons and other evidence connected with the incident.

Paxton said the reward is still being offered for information leading to the recovery of Casto’s gun.

Sheriff’s Lt. Col. Gene Moss said the recovered items -- including two firearms, some clothing and Casto’s bulletproof vest -- were found at a Buford residence where the alleged gunman, 19-year-old Nakitta Holmes, lived.

Bond has been denied for Holmes and a 16-year-old from Buford, who have each been charged with armed robbery and murder in connection with the grocery store incident.

Sharod Johnson and Tyrice Kendall Adside, both 18 and of Forsyth County, were also denied bond and face the same charges.

Authorities have said Holmes, Adside and the 16-year-old entered the grocery store through a back door that Johnson had left unlocked for them after closing time.

Johnson had been a cashier at Ingles for about six months.

He reportedly told investigators the other three suspects instructed him to lure Casto, who was from Winder, and a female employee to the back of the store that night.

Johnson’s and the woman’s hands were bound with duct tape and they were led to the store’s office by Adside and the youngest suspect. Casto remained in the cooler with Holmes.

Paxton said Casto was disarmed, his hands were bound and his eyes were covered with duct tape before he was shot.

When Johnson and the others returned, Casto was dead.

Paxton said Holmes, who has refused to cooperate with the investigation, was the last person seen with Casto’s gun.

Though they have not yet been charged with them, the suspects in the Ingles case are thought to be connected to other armed robberies in Forsyth and Gwinnett counties in August.

Paxton said investigators are “meticulously” going over the evidence that has been collected from the crimes.

The weapons and clothing authorities have found are thought to have been used in the armed robberies that led up to the Sept. 5 shooting, Paxton said.