Police are also offering an $152,000 reward for information leading to the arrest, ABC News reported.
The two Tupelo officers were shot Monday as they confronted the bank robbers during their getaway.
Officer Gale Stauffer, who served in Iraq and is the father of two young children, died in the shooting.
The second officer, who has not been identified, is in serious condition at the hospital.
A candlelight vigil was held for Stauffer earlier this week, and his funeral is Friday, ABC News said.
"The overwhelming love and support that this community has given us has helped us make it through," said Debbie Brangenberg, Stauffer's mother.
Authorities said they are looking for a thin man, 5-foot-9 to 6-feet tall, who may be black with a light complexion.
He was seen in the surveillance video wearing khaki pants, white Converse shoes and a blue ski mask.
Anyone with information is asked to call the FBI's tip line at 800-CALL-FBI (800-225-5324).