Horry County officials say Charles Dwight Ransom, 37, escaped fromJ. Reuben Long Detention Center Monday.
He was being held on a drug charge.
They say Ransom assumed the identity of the man he was arrested with, Nathaniel Mack Martinez.
Martinez was scheduled to be released Monday at 5 p.m. County officials say he gave his armband identification to Ransom, and when Martinez was supposed to show up to the housing unit to be released, Ransom responded instead and was let go.
Ransom and Martinez were arrested on November 17 by the Horry County Solicitor's Office Drug Enforcement Unit.
Nathaniel Mack Martinez was charged with two Counts of Trafficking in Cocaine and two Counts of Manufacturing drugs with intent to distribute, MDP.
He is now also charged with Aiding escape.
Ransom was initially charged with one count of Trafficking in Cocaine, but a warrant has since been obtained for escape.
Horry County Sheriff's Major Joey Johnson says they were aware of the escape a few hours after it happened. He says Martinez complained that he hadn't been released and jail workers figured out the two had switched arm bands. Major Johnson says they didn't tell the public because they hoped Ransom was still in the area and a task force was looking for him.
Martinez remains in jail.
You're asked to call J. Reuben Long Detention Center at (843) 905-5140 or 911 if you've seen Ransom. He should be considered dangerous and should not be approached.
A reward is being offered for his capture.