jim kavanaugh, we'll throw it to you since your name was evoked by clint there. i want you to react to some of the things that clint brought up and i want to ask you about police dogs searching the area. and they're explosion detection dogs. talk to us about what they're trained to detect and why they're doing such a thorough search and whether that's indicative of whether there could be more devices. >> when we go to these scenes, we always sweep for secondaries. that's on the top of the mind of all of us. is the device just meant to lure others in? we have to sweep for secondary devices. i like to say you have to -- when you hear an explosion, don't run toward it. take cover, there could be another. and we always prepare for that. we've had entrapment devices. i've had them over many years, eric rudolph is a famous one who planted a device to kill others, whether law enforcement or -- >> explain what you mean there, an entrapment device. >> well, one device goes off, emergency, fire, police, ambulance, investigators respond. and then the killers wait. the bombe

joining us again from nashville, jim kavanaugh, former special agent in charge and msnbc law enfornesmentnalyst. jim, extraordinary. first what do you expect to hear from investigators? what should they know by now and then get to the 500 leads. >> pretty normal in a case like this. we computerized leads, track them. fbi does, atf does. systems do that. a large explosion like this, you have tons of leads pouring in and you have to catalog them and computerize the leads. >> okay. >> that's pretty normal. hoping to hear maybe they've identified a person they think's involved. like we talked earlier. the cameras along second and tips tip s to -- tips to come in. lar rewards offered. i'm sure a tag number who owns that r v and may have a name. once a name is given to investigators, that's the white collar side we don't see. on the street we see agents working the bomb, outer perimeter picking up forensic pieces and examining them, but we don't see the met propolitan detectives and be command post goes with leads throughout the city to ask the questions and get the information, get the tips, y

jim kavanaugh, extraordinary times. thank you for breaking it down for us. >>> meantime, everyone, the day's other big breaking news. millions of americans staring into a financial abyss. more than 14 million could lose enum employment benefits by end of the day if the president doesn't sign the new covid relief bill. right now he's refusing to sign it unless congress boosts direct payments from $600 to $2,000 per bern. a move congressional republicans already blocked. go to nbc's josh letterman in west palm beach, florida, right where the president is spending his holidays at mar-a-lago. took months for congress to pass this bill. how are they reacting to the president holling it up in the final hours? >> reporter: deep frustration among both democrats and republicans in congress, alex. republicanly because they left town thinking was a done deal and did it because the white house was saying, publicly on tell vevision as well as lawmak on capitol hill the president intended to sign it. the situation might be differ if

jim kavanaugh, thank you, and welcome. really appreciate you being here for all of this. jim, we take a look there, and the fbi is now taking the lead in this investigation. what have we learned in the 23 or so hours since this took place that gives us clues as to who may be behind this? >> right. so, we have got to look at the purpose here. there's a very deliberate planning. there's a lot of effort in this. this was a large explosive device. it causes structural damage, sent fragmentation for blocks, left a pretty good crater in the seat of the blast there, so there's a lot of planning, there's a lot of activity to do this. that rv could be his own. it could be rented or stolen. it could be more than one person involved. then they had to make a tape recording. that had to have been planned. there's a countdown. so, there's a lot of planning involved. what we don't know, and one of the key things we need to find out is, was the bomber or bombers inside the van or not? there is some reports, kendis and lindsey, you talked about, you know, some human remains found. that cou

we spoke to atf former special agent jim kavanaugh the last couple minutes.t was an ied, and obviously caused some extensive damage. the mayor also saying it was done when no one was around. it's 6:30 in the morning downtown nashville. they got a little bit of snow yesterday. it was quiet. three people sent to the hospital. the mayor saying it could have been much worse. the mayor encouraging everybody to stay home with their families and be safe. but clearly an investigation underway. we'll continue to follow that story and bring you updates. >> coronavirus meanwhile is ravaging california with death toll there spiking by more than 100% in the last two weeks. hospitals are bracing for weeks. hospitals are bracing for another swell in new cases from holiday gatherings this week and that's on top of the surge from thanksgiving. louisiana county has been hit the hardest. 148 deaths from covid were reported there thursday which topped the previous all-time high set on wednesday. megan fitzgerald joins us now from los angeles. merry christmas to you. another seri

let's bring in jim kavanaugh, retired atf special agent in charge and nbc news law enforcement managerbc, former assistant director for counter intelligence. you know, let's start with this first question as we look at the new information that has come in so far, jim. you're there in tennessee. what are you seeing and learning on the ground that you've seen so far? >> well, this is a massive blast, richard. it shook the city. there was a low ceiling. we had flight flurries last night in nashville and it shook the city. it was felt miles away. watching the video of it, this was a very large explosion, explosive device used in there. it could have been a blasting agent like ammonia nitrate. i haven't seen enough angles to be able to tell what type it was. sometimes those are indicators but it was very large. it was very planned. it was -- the recording to get people away tells us a little bit about the intent of the bomber. you know, you endanger people when you detonate a large and i imp viced explosive device. we shouldn't go too far praising someone from trying to save lives. there wa