A jury deliberated about two hours Thursday before finding Charles M. Tyler guilty of gunning down a security guard to steal a load of copper.

Judge Carl C. Brown Jr. sentenced Mr. Tyler, 27, to the mandatory sentence -- life in prison -- following the jury's decision in Richmond County Superior Court.

Mr. Tyler was convicted of felony murder, armed robbery, burglary and a weapon violation for the June 4, 2008, slaying of 59-year-old David Fulkrod.

Mr. Fulkrod was shot in the face in the doorway of the guard office at CMC Recycling, a place where Mr. Tyler had also worked for a time.

Mr. Fulkrod's possible identification of Mr. Tyler is the reason Mr. Tyler shot him at the start of the crime, Assistant District Attorney Falin Rogers told the jury in her closing argument.

After shooting Mr. Fulkrod, Mr. Tyler drove a 26-foot U-Haul truck to the building where he used one of the business's forklifts to load a 4,000-pound bundle of copper wire into the truck, Ms. Rogers said.

Mr. Tyler rented the U-Haul truck and a storage unit before the robbery, Ms. Rogers said. He also downloaded information from the Internet about forklifts, the weight-bearing capabilities of various U-Haul trucks, and the locations of various recycling centers in the southeast.

But Assistant Public Defender Benjamin Jackson argued to the jury that there was reasonable doubt because other possible suspects existed.

Just because Mr. Tyler had copper doesn't mean he committed the crime, one that the state theorized could have been committed by two men, Mr. Jackson said. Only one person has been charged with the crime.

Mr. Tyler had prior convictions for thefts. Sheriff's investigators suspected he was involved when the U-Haul truck he rented was found with copper debris inside.

Mr. Fulkrod was unarmed when he was shot. He had worked for Sizemore Total Control for 18 years.