on the isis threat we've got polo sandoval and phil mudd and julia are here to break it down. >>> first, the breaking news on the berlin christmas market attack. tunisian state tv just announced three arrests in connection to the plot. the three men between the ages of 18 and 27 are described as terrorist elements. this new information emerging as new video of the slain attacker aniece amry pledging his allegiance to isis as that video continues to circulate. in this video amri says he would serve baghdadi and vow to slaughter the crusaders who are shelling the muslims everyday, but he doesn't refer to monday's attack that left 12 dead and injured 48. one of those victims the body of an italian woman was transported to rome this morning. cnn international correspondent nina dos-santos is in milan for us. you spoke with counterterrorism officials there who said amri had, quote, hallmarks of being