Itasca police say a door leading to the courtyard did have an alarm that had sounded. But staff claim when they checked on it, they did not see anyone.
Police say there are conflicting stories and that criminal charges are possible. The nursing home said it is co-operating and that "the arbor has appropriate and approved policies and procedures for supervising its residents and keeping them safe."
"It has continuously trained all staff regarding these policies and they remain in effect for the protection of the residents," the nursing home added.