Criminal Minds Season 6 Episode 6 (Criminal Minds s06e06) with title “Devil’s Night” aired on Wednesday, October 27th 2010 at 09:00 pm via CBS Network.
Here is summary for Criminal Minds Season 6 Episode 6 :

For the past three years a killer has been active in Detroit during the pre-halloween celebrations, but this year the BAU is there to catch him.