to catch a serial bomber, after a fifth explosion in texas, at this fedex center near san antonio. >> there were nails and metal in the bomb. the package was going to austin. >> reporter: a female worker treated for minor injuries. >> get me an engine out there, as well, just in case there's any subsequent bombs. >> reporter: the device that blew up shipped from this austin fedex store. police shutting it down today. and late tonight, a new clue. we've now learned fedex has recovered a second device shipped by the same person that they've now turned over to investigators. >> it's extremely important to have an unexploded package or bomb, because it then gives you the intricacies of how he built the bomb, which will tell you about expertise, it may give you a greater likelihood of tracking down the materials he used. >> it's in your workplace and we deliver packages on a daily basis. so, you never know what might happen. >> reporter: the police chief today briefing austin city council. >> we've now brought in the new element that that device was actually going through one of