A Grand Prairie Independent School District teacher has been suspended after the district learned he was arrested three years ago and charged with threatening a mass shooting.

Christopher Durham, 46, taught at Grand Prairie Collegiate Institute.

He told students late last week that he was famous and suggested they look him up on the internet, parents told NBC 5.

They found news reports from Oklahoma City that Durham had allegedly threatened a judge and lawyers involved in his 2013 divorce case.

According to court documents, his own lawyer reported that Durham said he was capable of a mass shooting like the one at Sandy Hook Elementary School in Connecticut.

His trial is set for next month.

Reached by telephone late Tuesday, Durham said the charges are completely false and he's confident he will be exonerated.

He declined further comment and referred questions to the district.

Despite the charges, Grand Prairie ISD spokesman Sam Buchmeyer said a background check before Durham was hired in August did not raise any red flags, even though it showed Durham's 2013 arrest for making harassing or threatening phone calls.

Buchmeyer said the district does not generally search applicants' names on websites like Google but is reviewing its system for vetting new teachers.

The background check also failed to reveal Durham was fired from an Oklahoma charter school soon after his 2013 arrest and that he was re-arrested in Tarrant County in July -- one month before he started working for the district.

Some parents of students at the school faulted the district for not being more thorough.

"I was really surprised because I believe the school district, taking care of children, should have done a better job than that," said Augustine Egeonu.

"You would think they could Google it," said Jennifer Gilbert. "But I guess they didn't."