The Broward County Sheriff's Office said the suspect, described as an African-American in his 20s, tried to carry computers out of BJ's Wholesale in Parkland without paying Oct. 30, the South Florida Sun-Sentinel reported Thursday.
Octogenarian store employee Bernard Sobol noticed the alleged thief while checking a customer's receipt and began chasing him, investigators said.
They said the man knocked Sobol to the ground, but the action caused him to drop the computers.
A witness chased the man outside but abandoned the pursuit when the thief revealed a silver object concealed under his shirt.
Sobol suffered a broken rib and some scratches. Investigators had yet to find the suspect.