- Derrick Estell escaped an Arkansas detention center on Sunday
- He was talking on the phone with his mother when he bolted, authorities say
- His mother Glenda is arrested for allegedly helping her son escape
- Her son remains at large, a sheriff's deputy says
(CNN) -- The mother of Derrick Estell -- the inmate who brazenly escaped an Arkansas detention center this week -- was arrested Friday for allegedly helping her son.
Glenda Estell, 54, was arrested without incident around 10:40 a.m. at her 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.
Her son, Derrick, remains at large.
According to Garland County Deputy Sheriff Scott Hinojosa, investigators have received tips on Estell's whereabouts in recent days "but unfortunately, at this point, none of them have been credible."
Surveillance video from Sunday shows Estell talking on the phone and then bolting through a 12-by-30-inch reception window at the Garland County Detention Center while another prisoner distracts deputies.
He then ran out the front of the jail -- with a deputy close behind him -- then jumped into a waiting car and sped away.
The getaway car was found, abandoned, just a few minutes away but there was no sign of Estell.
The vehicle was driven by Tamara Upshaw, who 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's arrest.
The same document details the Sunday phone call between Glenda and Derrick Estell, while the latter was in the detention center's booking room.
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?"
The video shows Estell suddenly dropping the phone, jumping up on the counter, then escaping.
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.