customs enforcement, shep. they tell us the information is still scarce but apparently two of these ice agents were based in mexico city where about two dozen other agents were also based and driving from mexico city to monterey when they were attacked by unknown assay lengths. so we do not yet know if this is cartel violence. reportedly, one of the agents is in critical condition. the other one is in stable condition. and for context, this area around monterey has been a war zone on mexican police. 20 of them killed so far this year. and last year, more than 70 mexican police officers killed in and around monterrey, shep. >> shepard: why so much violence against police in that particular area, trace? >> because the cartels down there are fighting for territory. specifically the zeta cartel and the gulf cartel. that's a very important corridor for the drug cartels. because, once you get outside monterrey toward the u.s. border and into laredo, texas. there are two major freeways