HIGHLANDS RANCH, Colo. — A former teacher at ThunderRidge High School is under arrest on several charges related to child pornography, stalking and burglary, and investigators are looking into two separate cases against him, officials said Monday.

Jeffrey Joseph Falk, 51, was arrested Sept. 21 and briefly released on bond before being arrested in a separate case Sunday, according to court records.

Falk taught at ThunderRidge High from 1995 until 2014, according to Paula Hans, spokeswoman for Douglas County Schools. Falk holds a valid teaching license in Colorado for math and music.

ThunderRidge principal Chris Tabeling, in a letter sent to parents that was posted on the Douglas County School District’s Facebook page, said the school and the district are taking “this matter extremely seriously and we are cooperating fully with law enforcement.”

Falk faces eight charges — seven felonies and one misdemeanor — from his Sept. 21 arrest: Sexual exploitation/child-induce/entice; sexual exploitation/child-sell/publish; burglary 2 of dwelling; three counts of sexual exploitation of a child with video of 20 or more items; stalking-emotional distress; and computer crime unauthorized access.

Falk’s next court appearance is Oct. 15.

Second case investigated

Michelle Yi, spokeswoman for the 18th Judicial District, said Falk is facing four charges in the second case: sexual exploitation/child-induce/entice; sex exploit child-video/20 or more items; stalking-threat and follow/contact/surveil; and computer crime-unauthorized access.

A formal filing of charges in the second case is expected during a court hearing scheduled Oct. 30.

“He was always very paternal and tried to act like our father. I never suspected anything but now it makes sense,” a former student told FOX31 Denver’s Justin Joseph.

Falk remained in jail Tuesday morning with bond set at $600,000.