NEW YORK -- Robert Singer, the chief operating officer of the National Children's Museum, remained in custody Wednesday, charged with sending child pornography on the Internet.

Singer and his family have lived in a quiet neighborhood in Lake Barcroft for about 15 years. Neighbors there said they were taken by surprise when they heard about the charges.

Related: Watch The Report

Singer, 49, allegedly sent 18 pictures of child pornography to an undercover NYPD detective posing as both a 33-year-old mother and 12-year-old daughter after the two met in an Internet chat room, investigators said.

"We know him as a nice person, good neighbor," one neighbor said. "We're completely shocked by what we've learned here, astounded by it. Which means you can't tell what's going on in anybody's house, in anybody's mind."

The federal charging documents accuse Singer of using the screen name "badboy2." The contents of computers he used at home and at work as chief operations officer at the National Children's Museum were searched and evidence was seized.

Prosecutors claim Singer accessed an Internet chatroom called "Cuties" and sent dozens of images of child pornography to someone he thought was a woman and her 12-year-old daughter, according to court records.

The complaint said Singer told the mother and daughter his office was near the monuments. The administrative offices of the Children's Museum are located at L'Enfant Plaza near the National Mall.

The museum released a statement saying that Singer had been suspended from his job and "barred from the property."

If convicted, Singer could face up to 180 years in prison.