(CNN) -- A man who escaped from an Arkansas jail last week might be headed to a county in the neighboring state of Missouri, a sheriff's deputy said Monday.
Derrick Estell and Tamara Upshaw, the woman alleged to have driven a getaway vehicle, may try to go Dallas County -- a place Estell has visited before, according to Garland County Sheriff's Department Deputy Scott Hinojosa.
Tips on Estell's whereabouts have run into dead ends and law officers in Dallas County were working to see if he were in that community.
July 28 surveillance video from Sunday shows Estell talking on the phone and then sliding through a 12-by-30-inch reception window at the Garland County Detention Center while another prisoner distracts deputies. He then runs out the front of the jail -- with a deputy not too far behind him -- jumps into a waiting car that speeds away.
The getaway car was found, abandoned, just a few minutes away but there was no sign of Estell.
Estell's mother was arrested Friday for allegedly helping her son.
Glenda Estell, 54, was arrested without incident around 10:40 a.m. at her home in Hot Springs, Arkansas, according to the arrest report. She is set to appear in court August 13 on one charge of assisting in or furnishing an implement of escape for an inmate.
Upshaw had been staying with Glenda Estell and was with her the day of Derrick's escape, according to the affidavit laying out probable cause for Glenda Estell's arrest.
The same document details a July 28 phone call between Glenda and Derrick Estell, while the latter was in the detention center's booking room, just before the escape.
At the beginning of the conversation, Glenda Estell says "it's all good," then asks if his shackles are off and questions "is there two or three in there?"
Previous phone conversations between mother and son that "all have random mentions of the plan for Derrick to escape custody, just at various intervals between normal conversations," the arrest affidavit states.
Derrick Estell has a lengthy rap sheet, which includes charges of aggravated robbery, breaking and entering, and burglary among others.