Johnson pleaded guilty to second-degree assault and a weapons charge, and was ordered to remain on a medication for an undisclosed mental illness.
But in May, Johnson's probation was revoked, although court records don't indicate why. A warrant was issued for his arrest three days after his probation was revoked, but court records don't indicate if he was ever arrested.
Johnson's attorney at the time, Eric Barnhart, said Wednesday that Johnson was a productive part of society "when he was taking his medication," but struggled when off of it. Barnhart said he is not currently representing Johnson and declined to disclose the mental health condition or comment further.
The probable cause statement said Johnson also had prior convictions for drug trafficking and drug possession.
The school's website said Elsenrath has a bachelor's degree from Missouri Valley College and an MBA from Lindenwood University. Elsenrath, of Winfield, Mo., has worked in financial aid for 15 years. Police say Elsenrath is in his 40s.
The school has about 180 students in programs including business administration, tourism and hospitality, paralegal studies, fashion, and retail and interior design. It relocated to its current building from another downtown building in 2010.
The school will be closed until 8 a.m. Tuesday. Several messages left Wednesday with the school's president, Cynthia Musterman, and members of the staff were not returned.