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A Washington, D.C., pediatrician widely respected for treating children in the city's poorest neighborhoods for decades was arrested Wednesday and charged with downloading child pornography, according to federal court documents.

The man, Dr. Robert Paul Dickey, 73, was charged with two federal counts of receiving and possessing visual depictions of minors "engaging in sexually explicit conduct."

The doctor was even allegedly viewing a child porn site on his desktop computer when police and FBI agents showed up to search his home, according to a complaint filed Wednesday in U.S. District Court in Washington.

The complaint, which NBC News isn't publishing because of its sexually explicit nature, said Dickey acknowledged "that he visits child pornography sites, downloads child pornography and stores it on an external hard drive."

For at least 44 years, Dickey was considered a pillar of the community, treating children in Washington's poor neighborhoods south of the Anacostia River. As long ago as 1973, he was recognized in a profile in The Washington Post for serving "as an old-fashioned small town doctor" for hundreds of impoverished children a week.

NBC Washington: D.C. pediatrician charged with possession of child pornography

Dickey was busted through a tip from the National Center for Missing and Exploited Children based on information provided by Microsoft Corp., the complaint said. It said that on April 3, an Outlook user uploaded approximately 14 pictures of child pornography from an account with the username "Robert Dickey."

Investigators traced the computer's IP address to Dickey's home in Southeast Washington, the complaint said. It said they found explicit images of prepubescent girls in sex acts with adults on the hard drive.

Dickey's grandsons, one of them 9 years old and the other an infant less than a year old, live with him in the same house, the complaint said. Their whereabouts weren't made public Wednesday.

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