If you were fingerprinted by the police and the charges were later withdrawn, dismissed, stayed, peace bond, absolute or conditional discharge then you require a file destruction to remove your prints, photos, court and police records.
If you fail to do so, you criminal charge can be seen on a criminal record check which could affect your ability to obtain employment and travel to the US. Many people believe that because it was not a full conviction then they are free, but that is not necessarily true.
Here is an example of what a file destruction looks like once approved by the police: