Limit junk science testimony
Too many trial judges allow pseudo-expert cops to testify as expert witnesses on such topics as illegal drug sales and gang activity. Here is a Second Circuit case that at least puts brakes on testimony that masquerades as coming from the expert realm, but instead tries to introduce factual allegations that would not come in without expert testimony and that cannot come into evidence with expert testimony, either. U.S. v. Mejia, ___ F.3d ___ (2d Cir. 2008).
Thanks to a criminal defense listserv member for posting this case.