WASHINGTON — The Fairfax County police have issued a warrant on one count of indecent liberties against a high school teacher already facing two such charges in Loudoun County.

Andrew Robison, 29, of Centreville, was charged with two counts of indecent liberties by a custodian last week in Loudoun County after allegedly having two inappropriate encounters with a student. He was a teacher at Potomac Falls High School.

Loudoun County detectives informed Fairfax County detectives about their investigation, which led them to believe that the teacher and student had an encounter in Fairfax County as well.

Fairfax County detectives conducted their own investigation, which has resulted in a warrant for one count of indecent liberties against Robison in Fairfax County, according to a statement from the Fairfax County Police Department.

Robison is being held at the Loudoun County Adult Detention Center without bond.