A former Air Force non-commissioned officer was sentenced Monday to 120 years in prison after pleading guilty to child exploitation charges for producing sexually explicit images of children and sending them to an undercover federal agent last year.

In a two-year sting beginning in 2011, undercover agents chatted with William Gazafi, 44, of Lusby, Maryland, who worked in communications and maintained a security clearance with the Air Force. They talked with him in a chat room dedicated to incest, where he told them he molested young children and babies and drugged at least one victim. The Air Force has discharged Gazafi.

In August of 2013, Gazafi sent several images to an undercover agent, authorities said, three of which Gazafi said were produced after drugging a child.

According to Gazafi’s indictment, the charges are based on six images Gazafi produced, including one of a prepubescent girl restrained at her ankles with handcuffs, and another of himself and a five-month-old baby.

Federal Bureau of Investigation special agent Jacqueline Dougher said it is the worst child exploitation case she’s handled.

"You have the sadism, the tying of the kids, the drugging of the children, their ages, and you have him in the position he’s in," Dougher said. "I’ve been an agent for 16 years and worked in this unit for 13 years, and this was the worst case I’ve ever had."

Gazafi’s attorney, federal public defender Amy Steffan Fitzgibbons, did not return a call for comment on Monday.

Federal agents and task force officers arrested Gazafi in September at the Andrews Air Force Base as Gazafi was returning from a mission overseas.

In April, Gazafi pleaded guilty to six charges of exploiting children in order to produce child pornography.

An undercover federal agent first took notice of Gazafi in 2011, though the defendant didn’t begin sending images until 2013.

The undercover agent told Dougher, "look, this guy is a hands-on offender and if he’s telling the truth, we need to get on this."

"These images are horrific," Dougher said. "Once we figured out who he was, we put everything in hyper-drive."

After Gazafi’s arrest federal agents searched his home, where they discovered more than 15,000 explicit images — including about 1,000 of infants — and a bottle of Ambien, Dougher said. That’s the powerful sleeping aid Gazafi told an undercover agent he’d given to a child prior to molesting her. Agents also seized electronic devices Gazafi had been traveling with overseas, on which Gazafi kept thousands of images including those he sent to the undercover agent.

"We know he was taking them with him everywhere he went in an official capacity," Dougher said. "He was traveling with his collection."

Dougher said four victims have so far been identified but there may be more.

"We investigate cases every day that make us shake our heads, but for someone to sexually abuse a 5-month-old baby defies comprehension," said FBI Baltimore Division Special Agent in Charge Steve Vogt in a news release. "Cases such as this serve as a reminder that in this day and age, a person’s status and position doesn’t immediately make him trustworthy."