A now-former substitute teacher in Keys schools has been accused of possessing a huge cache of child porn.

William Britt, 55, formerly of Cudjoe Key, is charged with 123 counts of possessing child pornography and seven counts of possessing a photograph of a sexual performance by a child. All are felonies.

Records provided by the Monroe County School District's Human Resources Department indicate Britt earned $100 daily substituting at Horace O'Bryant Middle School, Sugarloaf School, Key West High School, Marathon High School, Poinciana Elementary School, Glynn Archer Elementary School and Gerald Adams Elementary School.

He was taken to the Monroe County Jail on Thursday on $145,000 bond.

In some cases, Britt, who started working as a sub in 2010, worked with prekindergarten and special-needs students.

In a prepared statement Friday, schools Superintendent Mark Porter said "at the time of his original hire, Mr. Britt was subject to and successfully passed all of the background screening and fingerprinting efforts that the School District requires of all employees. In fact, there is no indication in Mr. Britt's background of any prior criminal misconduct.

"There is also currently no evidence or indication that Mr. Britt committed misconduct in his role as a teacher or substitute teacher."

Monroe Sheriff's Office spokeswoman Becky Herrin said Britt came to the agency's attention after his former landlord saw child porn in a box as he was helping Britt move out earlier this month. The landlord called authorities.

Britt was arrested following a search of his recreational vehicle, parked at the U.S. Navy's Sigsbee Park, where he reportedly moved from Cudjoe. In it, Herrin said, detectives found the child porn along with a sawed-off shotgun and a loaded handgun.

During an interview with a detective, Britt said he knows he is "sick" and that he works at schools "because he enjoys the company," Herrin said.

Deputy Anthony Fuentes wrote in a report that pictures he saw from Britt's collection were "extremely disturbing," depicting naked children as young as age 6 performing sex acts. Evidence includes photographs, videos, computer hard drives and other digital storage devices.