Deny Palencia, 32, allegedly went to a pawn shop on Broadway Street in May 2011 and pawned a cell phone.
It wasn't until later, when a pawn shop employee was cleaning the phone so they could sell it, that the illegal pornographic images were discovered.
The employee called Houston police and investigators took the phone, surveillance video, pawn slips and other items as evidence in the case.
Police said forensic analysts recovered 966 images of possible child pornography from the phone. Of those, the National Center for Missing and Exploited Children identified 173 as known child pornography.
Investigators added that photos of Palencia were also on the device, saved within the same time frame as the illegal images.
Pawn shop employees and surveillance videos confirmed that Palencia is the man who pawned the phone to the store, police said.
Palencia was charged Thursday with three counts of possession of child pornography. As of Monday, he had not been arrested.