A Houston man, Nilanjan Brahma, age not listed, was sentenced Friday in Lubbock federal court to 21 months in prison.

Brahma admits in April of 2011 he was caught by an undercover Lubbock police officer who was posing on the Internet as a 13-year-old girl. Brahma admits he sent pictures of an erect penis over the Internet to the officer who was posing an underage girl.

The charge against him was attempted transfer of obscene material to a minor. No explanation was provided in court records as to why prosecutors waited to bring charges against him.