Arrested but NOT Convicted! 
Individuals who have been arrested and received either a Conditional Discharge, Absolute Discharge or had their charges Withdrawn, do not need a Pardon as there is no criminal conviction to Pardon. However, the arrest record and fingerprints still exist and can be viewed by law enforcement officials across North America. The photographs, file contents, and finger prints contained in the arrest file can be purged, or destroyed so that this information is removed from scrutiny and prying eyes.
The Importance of Record Removal 
The fact that this information still exists means it can have a derogatory effect on you if stopped at the border, or by local police for whatever reason. If this information exists on Government computer data bases it may also accidentally be released when random background checks are done for employment, schooling, vulnerable sector, or any other reason. It may also be leaked out if the computer system is hacked into as has happened recently in the news with Government Agencies such as the CRA and multinational corporations, such as Sony.
Be Smart 
It cannot be a benefit to anyone for this information to be floating around in cyberspace, and we would strongly suggest you have it removed, for the freedom and peace of mind it will bring to you knowing that your past is hidden from scrutiny and prying eyes is well worth the nominal cost.
Relevant media articles include:  A business man charged and investigated for possession of marijuana in 1990, which charge was later dismissed in Court was nevertheless still denied entry to the U.S. because of this old arrest record. The record was never removed from police computers
Read more: http://www.thestar.com/no_discretion_police_records_that_ruin_innocent_lives