OAKLAND (CBS SF) — A computer technician at Lawrence Berkeley National Laboratory was sentenced to 10 years in prison on Thursday for downloading child pornography while at work, according to the U.S. Attorney’s Office.

David Busby, 61, of Richmond, was convicted following a three-day trial that ended on Sept. 19 to possessing and accessing child pornography with intent to view the material, according to U.S. Attorney Melinda Haag.

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Busby was a registered sex offender based on a prior conviction, she said.

A network security analyst had detected traffic indicative of child pornography on the National Energy Research Scientific Computing Center’s computer network that was later tracked to a laptop computer used by Busby, according to Haag.

He worked part time at NERSC, which is affiliated with Lawrence Berkeley Laboratory, she said.

Shortly after the discovery, Busby allegedly admitted to authorities that he downloaded child pornography to two work computers, kept the material for a period of time, then deleted the images, according to Haag.

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Through a forensic examination 1,400 images had been deleted from the computers, she said.

Busby’s defense claimed he downloaded the pictures by mistake and intended to access legal child modeling sites.

He was indicted by a federal grand jury on July 9 in a superseding indictment, according to Haag.

Busby was remanded into custody after his trial and was also sentenced to 10 years of supervised release, she said.

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