Police have made a third arrest stemming from a retail theft investigation involving businesses in Guelph and Campbellville. The investigation was launched earlier this year by the Guelph Police Service due to reported retail thefts involving a group of people. The suspects were allegedly involved in the theft or attempted theft of almost $4,000 in merchandise during May and June. Earlier this summer, a 44-year-old Guelph woman and 34-year-old Guelph woman were both arrested and charged in relation to the case. This week, another 34-year-old Guelph woman was arrested.