ST PETERSBURG - Police have arrested a man they say is responsible for a string of convenience store robberies over the last month. Ryan McLain Fields, 24, of St. Petersburg was taken into custody Friday night after police say he robbed the Quick Thru Mini Mart at 4025 Fourth St. N. Police said Fields, armed with a knife, approached a male clerk shortly before 6:30 p.m. and demanded he open the register. The clerk, who armed himself with a 12-gauge shotgun, struggled with Fields. Other customers and neighbors jumped in when the gun accidentally discharged. No one was hurt, but the group held Fields until police arrived. While being interviewed, police said Fields confessed to three other St. Petersburg robberies and two others that he committed in other parts of Pinellas County. He was taken to the Pinellas County Jail on multiple armed robbery charges.