By Shereen Siewert

WAUSAU — A 32-year-old Wausau man who spent 12 years behind bars on child sex assault charges is in trouble again, after a tip from Google led police to discover dozens of photos and videos depicting child pornography on the man’s phone.

Kyleley E. Olds now faces 16 felony counts of possessing child pornography as a repeat offender, charges filed Monday in Marathon County Circuit Court. He is being held in the Marathon County Jail on a $10,000 cash bond.

Police were alerted April 4 via a cyber tip that Google search engines had detected images of child pornography on a phone that was later traced to Olds, according to court documents. The tip was routed through the National Center for Missing and Exploited Children, which is routinely notified when Google or other internet providers discover such images.

Google can detect child pornography with a widely used digital fingerprinting system — called “hashing” — that allows companies and law enforcement to detect known child pornography in electronic services like Gmail. Google said it has been using hashing since 2008.

The information was enough for investigators to secure a warrant. The resulting search turned up a notebook filled with writing that contained internet web pages containing potential child pornography, police said. Even more damning, however, were the graphic images and videos that depicted infants, toddlers, and elementary school children being sexually abused, according to court documents.

Court records show that Olds is currently serving a 10-year probation term stemming from a 2003 conviction of first degree sexual assault of a child. In that case, Olds was initially given probation and a suspended sentence, but in January 2009 his probation was revoked. During a revocation hearing, now-retired Judge Vincent Howard sentenced Olds to 12 years in prison, with 1,147 days credit for time served. He completed his initial prison term in September and was released, and is a lifetime sex offender registrant.

A preliminary hearing is set for April 18.