Allegations of misappropriation usually arise from a police officer or other public employee taking items that belong to the public entity or other persons and keeping these items for themselves.  The misconception is that just because these items are not being used, or have been sitting stagnant for long periods of time it is okay for the employee take them.  Examples of these items may be evidence that has been sitting in the evidence room for long periods of time or parts that are considered obsolete and that will most likely be thrown out anyway.   Regardless, of the condition these items are in, they still belong to someone else, i.e., the public entity the person works for.  Usually, the more serious problems usually arise when these items are taken and then sold to make a profit.  Technically speaking these items still belong to the organization and therefore the funds gained by their sale also belong to the organization. 

A good rule of thumb, is that if there is ever a question as to whether you can take something from your department, get permission from a supervisor in writing.  This goes hand in hand with the possible defense against misappropriation, which is being authorized to take the items.