this is not a theory
i re watched season 2 episode 8 (his right red hand)
the man poisoned Rebcca was wearing blue t shirt the same man arrived in  earlier in limousine and motorbike and minelli met him ( i couldnt see his face clearly )
also minelli was looking at picture (looks like kirkland ) and has somthing to tell lisbon but he didnt
if anyone know who is this or what is this about plz tell