A Secret Service officer pleaded guilty Wednesday to two federal crimes, after sending explicit images to a police officer posing as a 14-year-old girl online.

According to the Justice Department, Lee Robert Moore, 38, was an agent assigned to the White House before he was arrested in November 2015. He's been in custody since his arrest.

Moore, of Church Hill, Md., sent sexually explicit text messages and at least one sexually explicit photo of himself to a Delaware State Police officer posing as a 14-year-old girl on the website Meet24. He also sent voice messages, according to a statement.

The chats were sexual in nature and some even took place while Moore was working at the White House.

After his arrest, Moore admitted to having similar interactions with three other minor girls, one in Florida, one in Texas and one in Missouri. He admitted to sending sexually explicit images of himself and convinced those girls to send sexually explicit photos of themselves as well.

He pleaded guilty to all charges and has yet to be sentenced.