Jennifer 'JJ' Jareau:  This postmark .
Cal McGee: Excuse me ?
Jennifer 'JJ' Jareau: Kansas City .
Cal McGee: Right .
Jennifer 'JJ' Jareau: Missouri . We 're in Kansas City , Kansas .
Cal McGee: Yeah , well , they 're just across the river from _ one _ another .
Jennifer 'JJ' Jareau: No , what they are is right across the state line .
Jennifer 'JJ' Jareau: Hotch
Jennifer 'JJ' Jareau: , it 's federal .
Aaron 'Hotch' Hotchner: What ?
Jennifer 'JJ' Jareau: If we want this case , it 's ours . It 's federal . This letter came from across the river , from Kansas City , Missouri .
Aaron 'Hotch' Hotchner: Interstate communication .
Jennifer 'JJ' Jareau: Puts it in federal jurisdiction .
Aaron 'Hotch' Hotchner: Sir , this is now a federal case . I would like to retain Detective McGee as a consultant .
Capt. Wright: Whoa , whoa . You 're not opening any investigations in my jurisdiction .
Aaron 'Hotch' Hotchner: I do n't wanna fight with you , even though this is a federal case . If we develop any information , I will come to you and your men will make the arrest .
Capt. Wright: And why would you do that ?
Aaron 'Hotch' Hotchner: Because that 's how we operate .