Garchik said, “Well, this is a lot of damage for a stick of TNT or even a pound of Semtex. Maybe it was a cocktail of components. Maybe HMX or CL-20. That stuff is scary powerful. They’re all in the family of most potent non-nuclear high explosives. But it most likely wasn’t military ordnance.”
“How do you know that?” asked Stone.
Chapman answered. “White smoke on the video. Military grade is oil-based, leaving a black smoke trail. White is usually commercial.”
The ATF agent smiled appreciatively. “You know your stuff. We’re bagging and tagging now. Taking residue from the blast seat.” He pointed at two burly black Labradors being walked around the grounds by their handlers. “Roy and Wilbur,” he said. “Those are the dogs’ names,” he added. “Dogs are the cheapest, most reliable bomb detectors in the world. One of my dogs can screen an entire airport in a couple hours. So they’ll burn through this whole park in no time. Find bomb residue my guys won’t even be able to see with all our fancy technology.”
“Impressive,” said Chapman.
Garchik continued with enthusiasm. “There aren’t even any machines in existence that can measure accurately the power of a dog’s nose. But I can tell you that people have about 125 million smelling cells in their nasal passages. Our Labs have twice that. We’ll run all the evidence up to our Fire Research Center in Maryland. We can torch a three-story building up there and have a hood large enough to capture every molecule of the burn-off. Be able to tell you exactly what was used.”
Stone said, “Anything left of the guy in the hole?”
Garchik nodded. “Bombs throw debris three hundred and sixty degrees. We’ve pulled body parts out of tree canopies, off surrounding rooftops. Two, three blocks away. Found a piece of a foot on the White House lawn. A partial index finger on the roof of St. John’s Church. Then there was tissue, brain matter, the usual stuff. DNA field day. Guy’s on a database somewhere we’ll know soon enough.” He nodded at the NRT truck. “Of course, the first thing we did was shut down the area and send in our dogs.”
“Secondary strikes,” noted Chapman.
“Right. They’ve made that a fine art in Iraq and Afghanistan. Trigger off a bomb, everybody rushes in to help, and they pop the secondary strike to take out the first responders. But we found nothing.” Garchik added in a proud tone, “And our Labs are exceptional. They’re mostly service-dog-school dropouts that can sniff out nineteen thousand different explosives based on the five major explosive groups, including chemical compounds. We train them with food. Labs are land sharks, do anything for food.”
“They can never be fooled?” asked Chapman.
“Let me put it this way. Roy over there found a four-inch-square C-4 block that was covered in dirty diapers and coffee, packed in Mylar bags in cement-lined crates, sealed in foam and locked in a storage room. And he did it in about thirty seconds.”
“How is that possible?” asked Chapman.
“Smells occur at the molecular level. You can’t seal them up, no matter how hard you try. Plastics, metals, pretty much any container or cover-up method can’t trap molecules because those materials are still permeable. They can hold solids and liquids, and even gases, but smell molecules are something altogether different. They can pass right through those substances. If the detection method is sensitive enough it really doesn’t matter what the bad guys do. Trained bomb detection canines have an olfactory capacity that is humanly impossible to fool, and believe me, lots of people have tried.”
“How do you think this bomb was detonated?” asked Gross.
The ATF agent shrugged. “Basic rule of three. To make a bomb you have to have a switch, power source and the explosive. Bombs are just basically something that can violently expand at extremely fast speeds while trapped in a confined space. You can detonate a bomb any number of ways, but the basic two are via a timer and by what we call command detonation.”
Chapman said, “Meaning the person doing the detonation is present?”
“Either the bomber or someone else. And the ‘someone else’ is usually to safeguard against the bomber getting cold feet. Probably half the suicide bombings in Iraq are detonated by third parties for that very reason.”
“I take it you’ve been there,” said Gross.
Garchik nodded. “Four times. And to be frank, I hope I don’t have to go back.”
“So where was the bomb?” asked Stone. “On the blown-up jogger?”
“Nope, don’t think that’s possible,” said Garchik.
“Why?” asked Stone.
“He went to the dogs.”
“What?” said Gross.
“I’ll show you. Come on.”
CHAPTER 17
GARCHIK LED THEM to the ATF’s command unit. Inside he fired up an array of electronic equipment. Moments later they were watching some of the video feed from the night before. When a particular scene came up he froze it and pointed his finger at the screen.
“There. Like I said, he went to the dogs. Or dog, in this case.”
The image was of the man in the jogging suit. He was entering the park from the north. He was frozen right next to two uniformed officers, one of whom had a dog. The jogger was perhaps a foot from the canine.
Chapman said, “Is that a bomb detection canine?”
“Yes, it is. Secret Service’s. Now, I don’t think their dogs are better than ours, but I can tell you any person carrying an explosive walking that close to a bomb detection canine trained in this country is gonna get busted. I don’t care how he tried to hide it. That dog would be going nuts or else doing a passive alert, meaning he’ll sit right down on his butt. This dog was doing neither.”
“And you’d think if he was carrying a bomb on his person he wouldn’t have walked right next to the dog in the first place,” said Stone. “He couldn’t assume it wasn’t a bomb sniffer.”
Gross added, “Which means this wasn’t a suicide bomber. The guy jumped into the hole to avoid the gunfire. Looks like the bomb was in that hole.”
“Well, that’s progress anyway,” said Stone. “Ruling out the jogger.”
“Was it a pressure switch?” suggested Chapman. “Jogger hit it and boom.”
“That’s possible,” conceded Garchik, though he didn’t look convinced. “Accidental detonation, you mean.”
“Maybe. Did you find any evidence of another type detonation switch?”
“There’s a million pieces of stuff lying around here and we’re still looking. But to complicate matters a bit, Lafayette Park is home to a lot of static electricity.”
“And static electricity can set off a bomb,” said Chapman.
“That’s right.”
“But if you go to all the trouble to get a bomb into Lafayette Park, why would you build the bomb in such a way that it might trigger off accidentally?” asked Gross.
Garchik said, “Might be as simple as the folks who managed to get the bomb in here were better than the guy building the bomb. That’s not as implausible as you might think. Or it could have been on a frequency switch and something interfered with it.”
“The jogger was wearing an iPod,” Gross pointed out. “That could have interfered.”
“That’s possible, yes.”
“But are we really sure the tree hole was the source of the bomb?” asked Chapman. “We’re sort of jumping to conclusions here that it was.”
“We haven’t finished our analysis, but it’s a safe bet that was the bomb seat,” said Garchik.
Stone said, “Then are we sure that the bomb going off was an accident?”
They all looked at him curiously.
Gross said, “It had to be. Otherwise why would they set off a bomb that had no chance of killing the prime minister?”
“Unless it was set on a timer,” said Chapman. “The PM was supposed to be in the park last night. If it was set on a timer there’s no way to take that back.”
“And it was a coincidence that the man jumped in the hole and it went
off when it did,” added Garchik. “That works.”
“No, it doesn’t work,” countered Stone. “You’re forgetting the gunfire. Why have both the gunfire and the bomb? And if the gunfire wasn’t done remotely, then the shooters would’ve known the prime minister wasn’t in the park.”
“That’s not necessarily true,” said Chapman. “I’ll show you.”
She led them back outside, where she pointed to the trees in front of the Hay-Adams Hotel. “If they were on the rooftop garden back there then the trees would’ve hidden the park from their view. They hear the sirens and the motorcade coming. They wait for it to pull in, the prime minister to get out and walk to the park. Then they start shooting.”
Stone did not look convinced. “So you’re saying this elaborate plan was put together and the gunners were firing blind?” He shook his head. “If I were going to do this, at the very least I’d have one spotter with a clear view of the PM’s movements stationed somewhere near the park with a secure line of communication. I’m not shooting blindly through tree canopies. And if the PM doesn’t come to the park, I call off the mission. But if he does set foot in the park I can’t afford to miss.”
“And they did miss everyone,” Gross pointed out.
The ATF agent nodded. “It’s a puzzler all right.”
Stone turned to him. “So if you were going to pull off this bombing, how would you detonate, Steve?”
“Pressure switches can be problematic, particularly under these conditions. I mean, you’ve got a tree in a hole and a bomb somewhere near it. Maybe in the root ball, maybe under the tree. That’s a lot of weight. And people moving stuff around, digging. Chances are that pressure switch gets tripped accidentally. And once you cover the bomb up with dirt, what’s going to trigger it? Something has to cause the switch to engage. It’s called a pressure switch for a good reason. No, if I were going to do it I’d use a command control device, meaning remote detonation. Now, if they did that they might have used a cell phone, which would make our job a lot easier. Cell phones have a SIM card and all the components are serialized, so we can reconstruct the phone and maybe track down where and who purchased it. Of course if a cell phone was used, you actually have two phones. One planted on the bomb as the switch and the other to call that phone. We did find some bits of wire, corner of a transistor, plastic shell casing, leather—”
“Leather?” Stone exclaimed.
“Yeah, tiny patches of it. About a dozen pieces. Had some black markings on them, so the probability lies with it being part of the explosive. Still trying to determine what it is. But we will. And then we have to definitively determine if it was tied to the explosion. Not all the junk we find out here will be.”
“Could have come off the jogger’s trainers,” suggested Chapman. “His shoes were made of leather, right?”
“Yes, but the color’s off. I saw the video feed and the guy’s shoes were blue.”
“The black marks could be scorching from the bomb,” Chapman pointed out.
“No, the rest of the leather was brown. Probably has nothing to do with anything.”
“So right now,” Gross said, “you still can’t tell us how the detonation was done?”
“That’s right.”
“Why are you thinking the bomb was in the tree hole in the first place?” Gross said. “Apart from the location of the damage?”
Garchik said, “Follow me.” He led them to the site of the detonation and pointed into the hole. “Unless I’m reading this wrong, this is ground zero. Blew that tree right out of here, and it wasn’t light.”
They all stared down at the hole, which had become even wider and deeper because of the explosion.
“Okay, so what are we looking for?” asked Gross.
“Well, there was already a crater here. The excavation for the tree.”
“Okay,” said Gross. “So?”
Garchik made a fist and swung it downward. “When you smack the water with your fist, a certain amount of water shoots up on both sides of the hand. Simple concept of volume displacement. Same thing happens with a bomb. If the bomb is aboveground it acts like the fist. It’ll push downward, sideways and also up. But a bomb buried in the ground has a different effect. It will propel mostly upward because it’s covered by looser dirt. Path of least resistance. It still deepened the existing hole.”
“Causing a crater. A bigger crater than if the bomb had been aboveground,” said Stone slowly.
“But the bomb in this case was buried in the dirt, right?” said Gross. He looked at each of them as though waiting for their collective affirmation.
“I wish I could tell you for certain,” said Garchik. “Normally, making that determination is one of the easiest parts of the equation. But here we have a complicating factor. There was already a big crater here before the bomb went off.”
Gross looked confused. “I’m not exactly following you here.”
Stone said, “He means he can’t tell if the bomb was buried in the dirt or may have been in the root ball or even under the tree.” He looked at the ATF agent. “Right?”
“That’s right.”
“Does it matter?” asked Chapman. “In any case the bomb was placed in the park in that hole.”
Gross said, “That’s true. The question is, how did they do it? This is Lafayette Park, not some back alley in Baghdad.”
Stone looked around. Guns and bombs right across from the president’s house. There could only be one answer. “We’ve got a traitor somewhere,” he said.
Chapman added, “And if the PM hadn’t turned his ankle he’d be dead.”
Stone looked at her. “But more to the point, they got a bomb into Lafayette Park. Across from the White House. The most heavily guarded piece of land in the world. How?”
CHAPTER 18
AFTER A MINUTE OF SILENCE as they each thought about this question, Gross said, “I just don’t see how anyone could have managed that. This place is under surveillance 24/7.”
“That’s true,” said Garchik.
It is very true, thought Stone. “But all the evidence seems to point to that being the case. A bomb was planted in that hole.”
Gross looked at Chapman and then at Stone. “Do you realize how many people would have to be potentially involved in something like that?”
Stone said, “Well, for starters we need a list of anyone involved with the process of digging that hole and planting that tree. The National Park Service handles all that, but there would have been others involved too.”
Gross pulled out his phone and walked off a few feet as he punched in a series of numbers.
Stone turned to the ATF agent. “Once you determine what sort of bomb it was, what then?”
“We’ll put it on BATS. Bomb and Arson Tracking System. ATF maintains it. It has worldwide reference. Bombers don’t like to deviate from their formula, so they develop signatures. Pretty practical reason. Once they find a method that works, they don’t change it.”
“Because they might blow themselves up with a new method,” said Chapman with a knowing look.
“You got it. Bombers typically like to test out their stuff beforehand, and that’s another way we catch them. Blowing stuff up in the woods and somebody reports them. They never think to realize that they can check all their connections and switches without detonating. Because the bomb materials themselves will go off. The only weak points are the connections and the power source.”
“Maybe these guys like to blow stuff up for the hell of it. Like to see the boom,” observed Chapman.
“I do think that’s part of it,” replied Garchik. “So anyway, we’ll run it through BATS to see if the same signature appears on there. Then maybe we’ll know who our bomber is. I know a lot of signatures from memory, but nothing about this one is striking me as familiar.”
“Anything else?” asked Stone.
“Not right now.”
“Okay, thanks. And let Agent Gross know as soon as you have anything.”
r /> After Garchik walked off, Gross rejoined them, slipping his phone back in his pocket. “All right, I just set off a shitstorm back at WFO.”
Stone eyed the blast seat. “Getting back to basics. Who was the target?”
Gross glanced at Chapman and said, “Pretty clear. British PM.”
“He wasn’t in the park,” replied Stone.
“But he was scheduled to be. At just about the time the bomb went off. It was probably on a timer, despite what Garchik said. It got accidentally triggered, probably when that guy jumped in the hole.”
Stone shook his head. “A mission like this requires precision. By detonating, even accidentally, they give away their whole plan. They won’t get a second shot. They put everyone on alert for no reason at all. And your theory doesn’t explain the gunfire.”
“It doesn’t make much sense when you explain it like that,” admitted Gross.