Perp is accelerating operations and Clob has made some very good observations about the likely suspect. With bombs, increasing tempo gets you caught or dead. Years ago we had a guy who liked planting pipebombs around town. He was getting away with it and so he stepped up his pace. Then he got sloppy, forgot to grease the threads on his pipe and some powder got in there. Made quite a mess of his apartment when he put that last cap on....but he never knew it...