In this crime series, a crack team of FBI profilers fly from Quantico to the focal point of the criminal activity of various serial killers. There they investigate the evidence from the crime scenes, compose a profile and try to prevent the next fatal strike. Top brain was academic Jason Gideon who left the bureau after some difficult decisions. His more by-the-book operational right hand man Aaron "Hotch" Hotchner then took over the team. After Gideon leaves, David Rossi, previously retired, rejoins the bureau in an effort to make a difference in people's lives again and follow up on a case he worked years ago. The still juvenile Dr. Spencer Reid is an erudite on everything except real life, Penelope Garcia a brilliant computer whiz who gets access to any database etc. As they are mobile, cooperation with local police and FBI agents is important but often poses jurisdictional and other problems, as do some witnesses and suspects.