A Dawson County detention officer has resigned after confirming he accepted calls on his personal mobile phone from a female inmate under his supervision, according to officials.

Kevin Helmer, 39, resigned two days after an internal investigation indicated he had a long conversation with inmate Wendy Perry, 26, while he was on duty at the jail.

Helmer, who began work at the sheriffs department in January 2013, was stationed in a glass-enclosed control room where he was responsible for overseeing inmate activities in four jail pods.

What happened was, she came out of her cell and called his mobile phone, Dawson County Sheriff Billy Carlisle said. He can see her through the window, and hes looking at her while theyre talking. Not only was that a problem, but he also neglected supervising the other inmates.

Inmates have daily access to three pay phones in the jail pod area.

Perry has been in the Dawson County jail six times since September 2013: four times for drug court violations, once for shoplifting, and for possession of controlled substances, records show.

I think they built this relationship over time, Carlisle said. As part of their job, detention officers have regular contact with inmates -- they do nightly jail checks, move inmates in and out for court, take them to see the nurse or doctor at the jail, and feed them.

Evidently, at some point, he gave her his personal cell phone number.

Carlisle was unsure if there had been a sexual relationship between the two.

They had a relationship while she was out, he said. I dont know what kind of relationship.

Helmer violated the Dawson County Sheriffs Department Code of Conduct, G-030D, which states: Employees ... shall not become socially or emotionally involved with prisoners; and G-005C under the Oath of Office and Code of Ethics, which states: I will never act officiously or permit personal feelings, prejudices, animosities, or friendships to influence my decisions.

On average, the Dawson County jail has 160 inmates with 200 beds available.

There are six full-time employees currently overseeing the facility.

We really need seven full-time to be fully staffed, Carlisle said. When someone is out, we have to call in an off-duty officer to fill in.

Carlisle said budget constraints continue to hurt his office.

We cant hire the personnel we need, he said. And we cant keep experienced, good-quality people because theyve left for higher-paying jobs. We have no experience anymore and it hurts. This is the stuff we wind up with.