Investigators from multiple agencies are digging through the rubble left behind from Saturday's fire, hoping to find out more about how it started.
They believe the building's owner, Kenneth Rainwater, might be buried in the debris.
He became a suspect in the investigation after authorities found two notes in his car that were apparently meant for law enforcement.
According to authorities, the notes suggested the fire would be dangerous and that he would flee the scene.
Rainwater was expected in court this week on felony charges of possessing child pornography.
Information posted on the court website - Missouri CaseNet - about Rainwater's case includes notes about the fire and the letter left behind at the scene.
The post from the Holt County circuit clerk's office states that Rainwater "left a note saying he had military explosive experience - stand back and watch the fireworks."
A second note allegedly stated that "he couldn't get a fair trial and he was leaving the country."
Rainwater's next court appearance was scheduled for August 28.
The fire in Maitland destroyed the building, which dates back to 1880s. As of Tuesday morning, debris was still smoldering where the building once stood.