MARTINEZ (CBS SF) — An Oakley man attending college in Texas was extradited back to Contra Costa County on Tuesday.

The suspect, Tristan Amari Curl, pleaded not guilty on Wednesday to 10 felony charges alleging that he threatened to kill the principal at Freedom High School in Oakley, shoot students and rape underage girls.

READ MORE: COVID Surge: Brentwood School District Reports 18 New COVID-19 Cases

Curl is now facing additional allegations related to the distribution of child pornography. Officials say Curl is listed as a resident of Oakley, but has been in the custody of the Travis County jail since he was arrested in Texas on Nov. 20.

Curl, 19, was a student at St. Edward’s University and living in the Austin area, according to prosecutors. He allegedly made the threats over the internet. The case against him is the result of a two-month investigation involving the Oakley Police Department as well as personnel from the district attorney’s office and the FBI.

READ MORE: San Francisco Bay Area Public Health Officials Order Residents To Wear COVID Masks Indoor

Investigators believe that, with regard to the child porn charges, there may be additional victims here in Contra Costa County. They’re asking anyone with information about the alleged crimes to contact Oakley police Officer Casey Minister.

Other charges against Curl include making criminal threats, threatening a school official and stalking. He remains in custody on $500,000 bail.

MORE NEWS: 2 Arrested In Fremont Shooting Following Police Chase

© Copyright 2018 CBS Broadcasting Inc. and Bay City News Service. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.