The Williamson County Sheriff's Office is on the lookout for an alleged carjacking suspect.The carjacking happened around 8:30 p.m. Monday in the Cottonwood subdivision off South Berry's Chapel Road.The victim, a woman in her 50s, reported a man armed with a handgun jumped into the passenger side of her vehicle as she arrived home."He had a small handgun [and] ordered her to drive. He wanted money," Sharon Puckett with the Williamson County Sheriff's Department said.After pulling into Lynnwood Park in the nearby Fieldstone Farms subdivision, the woman was able to jump out of the car and run to some nearby homes.Officers flooded the area but did not locate the suspect.The woman was not seriously hurt."I'm sure she was frightened," Puckett said. "I'm sure she was very frightened."The carjacker was last seen running from the Lynnwood Park area.He is described as a black male in his early 20s. He is said to be between five feet, six inches and five feet, eight inches tall and 150 to 160 pounds.Anyone with information is urged to call the Williamson County Sheriff's Office at 615-790-5550 or Crime Stoppers at 615-794-4000.