WASHINGTON — Shaun Valente, 30, of Montgomery Village is pleading guilty to possessing and downloading thousands of images and videos of child pornography.

The U.S. Attorney’s Office in Greenbelt, Maryland says Valente’s plea comes after an investigation that started when Dropbox, the online storage platform, tipped the National Center for Missing and Exploited Children to the existence of the images on Valente’s account in 2014.

In 2005, Valente was convicted in Montgomery County Circuit court for the sexual abuse of a minor and for manufacturing child pornography.

According to the U.S. Attorney’s Office, Valente was sentenced to four years with all but 18 months suspended. The Maryland Sex Offender Registry lists the 2005 offense as the sexual abuse of a toddler.

According to the U.S. Attorney’s Office, the images found on Valente’s flash drives, computer and cell phone included violent images,  as well as the sexual abuse of children.

Valente is expected to be sentenced in November in U.S. District Court in Greenbelt.

WTOP’s Kate Ryan contributed to this report.