For the investigative report, Helling went to seven Kansas City-area farmers' supply stores attempting to buy large quantities of ammonium nitrate and insinuated that he was able to purchase twelve 40-pound bags of that fertilizer's pure form (totaling 500 pounds ) from Tonganoxie, Kansas-based McGraw's Fertilizer without further vetting; however, a Tonganoxie Mirror investigation uncovered that he had actually bought 20-10-10, a far less dangerous, commonly sold type of fertilizer named for the respective percentages of ammonium nitrogen (at levels significantly lower than the 70% needed to be considered of the pure form), phosphorus and potash in the blend.