The guard went outside to check the mailbox when the suspect jumped him from behind, snatched his weapon and wounded him. He then fled the scene.
The guard was taken to the Soroka Medical Center in Be'er Sheva where he received medical treatment and is expected to be discharged later in the day.
Police closed off the city from all directions in search of the suspect.
He was caught half an hour later when detectives in civilian clothes noticed a young man walking fast at the ONE shopping center in the city. When they asked him to stop, he tried to escape them, but they caught him after a short chase.
The gun, smeared with blood, was found hidden on his person.
The suspect was taken in questioning. "It was the quick and determined reaction of the detectives that led to the arrest of the suspect and thwarted the possibility of him using the gun to harm civilians," police said.
"All lines of inquiry are being examined: both criminal and nationalistic. The investigation is being conducted in conjunction with the Shin Bet," said Be'er Sheva police commander Efi Shiman.