have been carrying out these kinds of practices. officers with the baltimore police a year or two in some cases, that is kind of a step back for many people. >> i think in a case like this a lot, we have to look closely at training. what are officers taught to look for before they make that decision out in the street to make a warrantless stop? s a stop an investigatory stop? in theory should be just a few minutes. law enforcement uses that as a spring board this. almost follows a classic law exam pattern. they stopped him. never knew about the knife when they gave chase. if you are lawfully at that stop then you observe weapon with you can patdown. >> it raises issues. on the one end, the prosecution is going to make the argument that in terms of the investigation, you had no