GMAT Test Prep: CR-95244816 GMAT Critical Reasoning

Since the inception of Project Safe Neighborhoods five years ago, which seeks to reduce armed robberies by convincing people to sell their guns to the municipal government, the number of armed robberies has decreased by ten percent nationwide. Simultaneously, there has been a decrease in the number of reports in which convicted criminals are found to be in possession of guns. It is clear that Project Safe Neighborhoods has convinced many individuals not to own guns and thus not to commit armed robberies.

Which of the following, if true, most seriously weakens the conclusion drawn above?
Select one of the following answer choices