Joy L. Cassidy was picked up Sunday at the library, moments after police say she pulled through the outside drive-through and dumped a jar of mayo in the box designated for reading materials.
Cassidy was released from jail and faces a misdemeanor charge of malicious injury to property.
Boise police say Cassidy is under investigation for other cases of vandalism that started in May 2009. Library employees have reported finding books in the drop box covered in corn syrup and ketchup.