Helpless

Chapter 12

Hours after Rainy sent her e-mail, supervisory senior resident agent (SSRA) Walt Tomlinson entered the Lair with an air of urgency. Tomlinson had three grown daughters, so Rainy figured he’d give her a fair chance to make her case for Stern.

Tomlinson’s eyes looked troubled. Rainy read the deep creases defining Tomlinson’s sagging face like a palmist predicting a bleak outcome.

“Show me what you got, Agent Miles.”

Rainy showed Tomlinson several dozen of what she determined to be sexts culled from Mann’s computer.

“What do you make of these, Carter?” Tomlinson asked.

“No idea where they came from. We don’t think we’re going to get any CVIP hits on these.”

“What about our own database?” Tomlinson asked.

The FBI maintained a collection of their own hash values, nonofficial, of course, which came out of the Bureau’s national center.

Even a partial match would have generated a KFF, or Known File Filter alert. The KFF alert flags files identifiable from the FBI’s less extensive library of known images—most of which are depictions of child pornography.

“I checked and we got zilch,” Rainy said. “Whoever supplied Mann with these pictures is probably a new source to us.”

“So what’s next?” Tomlinson asked.

Rainy started to answer, but Tomlinson pointed a finger to forestall her.

“We’re going to continue with our forensic analysis here,” Carter said. “The log file data is useless to us until we can get valid IP and MAC address information.”

“And you can’t?” said Tomlinson.

“Mann’s basically encrypted all the header data on the file transfers. He used a new computer program that makes it easy to stay anonymous on the Internet.”

“What program is that?” Tomlinson asked.

“It’s called Leterg. We’ve busted a few kiddie porn collectors trying it out.”

Rainy made a face. The software name sounded nonsensical.

“It’s ‘Gretel’ spelled backward,” Carter explained. “Basically, if you think of Hansel and Gretel’s bread-crumb trick as an unencrypted data header that would allow us to follow a trail, Leterg makes it impossible for anybody to navigate a single path back to a source.”

“I’m not sure I’m following,” Tomlinson said.

Rainy followed perfectly well, but Tomlinson had several other squads under his command, including terrorism. He was a busy man with little time to absorb the nuanced details from the constant influx of new technologies.

Carter was more than happy to explain; he enjoyed talking technology. “If you laid down bread crumbs on your way home from work,” he began, “I could easily tell what route you took home.”

“Assuming the birds didn’t eat the bread crumbs, yes.” Tomlinson was always on the lookout for a hole in an explanation.

“Well, if every ten feet that single bread-crumb path split, went off in different directions, and stopped at different houses, could I ever tell where you started, or where you went?”

“No,” Tomlinson answered.

“Well, that’s exactly what Leterg does. Mann was communicating with somebody who was also running Leterg. Everything they sent went through that program, so we have no way of tracing it to a specific Internet hosting provider, let alone to a specific IP address.”

“That sounds pretty sophisticated,” Tomlinson said, rubbing at his temples as though the concept physically hurt.

“Actually, it’s pretty damn easy for somebody who knows what they’re doing,” Carter said. “And it’s a great way to cover your tracks. No evidence left to connect the criminal to the crime.”

“How did we catch on to Mann?” Tomlinson asked Rainy.

“We got a tip. Fed him some of our stock images and he bit. Got a warrant. Made the bust.”

“So how do we figure out Mann’s suppliers?”

Carter sighed. “Leterg requires that both the sender and receiver use the software to block our traffic analysis. Multiple people can use the same software, but every supplier has a unique key. If we had the computer of one of Mann’s suppliers, we could crack the encryption code, and you’d have the kind of evidence that makes the USAO tapdance.”

“Did Mann use a single source or multiples?”

“We think multiples. But everyone who supplied him was running Leterg. He probably installed the software and then went looking for suppliers who used the same CYA technology.”

“CYA?” Tomlinson asked.

“Cover your ass,” Carter explained.

Tomlinson nodded slowly and did not appear amused. “So do we know who these victims are?”

Rainy’s face brightened. Tomlinson had touched upon an important point.

“It’s my opinion that these images are of the same type, but not from a single source,” Rainy said. “I think they’re different girls—forty of them, by my count—taking pictures of themselves with their cell phone cameras.”

“And they sent their pictures to James Mann using Leterg?”

“I don’t believe that’s true.”

“Do we know how Mann got hold of these images?”

“No, sir,” Rainy said. “And it will stay that way unless we can crack the Leterg encryption codes.”

Carter held up his hand to indicate caution. “Remember,” he said. “If Mann had forty suppliers, we’ll need to crack forty codes. That’s a pretty unlikely outcome.”

Tomlinson thought. “A bit of a chicken-and-the-egg conundrum, it seems.”

Carter hoisted his hands skyward in a show of defeat. “Hence we come to a dead end. At least we can still get Mann for all the porn he downloaded.”

Rainy nodded in silent agreement. Thanks to the Adam Walsh act, James Mann met the interstate nexus requirement. The FBI could charge him with federal crimes simply because he had used the Internet to download pornography. As far as the law was concerned, Internet equaled interstate.

“Sounds good to me. Agent Miles, what’s the issue here?”

“The issue is these teenage girls who are sexting are stupid and haven’t a clue what they’re getting themselves into,” Rainy wanted to say. But she thought better of it. “Mann possessed a very large quantity of these unknown images—over three hundred. I think it’s important we confirm these images did in fact originate as part of a text message the girls themselves sent,” she said.

“Good. Then eventually you’ll get to that conclusion if the evidence takes you there.”

“We could speed things up, maybe even figure out Mann’s supplier if we could ID one of these girls. But there isn’t enough detail in these pictures for me to make one.”

“In your opinion, are any of these girls in immediate danger?” Tomlinson asked.

Rainy knew better than to lie. “No, sir,” Rainy said. “The images are consistent with other sexts that we’ve seen. But I’m wondering if somebody is hacking cell phones. If I could get some of Clarence Stern’s time, maybe put together a bigger task force, we could—”

“Out of the question,” Tomlinson barked. “Stern is fully booked investigating what may be a terrorist sleeper cell in Somerville. I can’t spare him.”

“But he’s the best at image manipulation.”

“Which is why he’s working terrorism.”

Rainy bit her lip. After 9/11, the FBI had rocketed right to the top of Washington’s most important agency list. Budgets ballooned as a result, but most of the money and resources went toward combating terrorism. Meanwhile, drugs, child porn, organized crime, mainstay assignments of the FBI for years, continued to skyrocket. Rainy couldn’t complain. It was well known that terrorism was job one at the FBI.

“Well, what do you suggest I do, Walt?”

“What I suggest you do is your job, Agent Miles.”

“Sir, if one of the girls finds out that her naked pictures are being passed around the Internet, it could end in tragedy. It could be another Melanie Smyth.”

Melanie Smyth was a fifteen-year-old girl from Newton who’d hung herself in the bedroom closet after her boyfriend posted the naked pictures she texted him to Facebook.

“Stern is booked. End of conversation. After you alert the major carriers about a potential hack, I suggest you talk with Mr. James Mann and figure out how we crack those Leterg codes.”

“He’s not going to know. Suppliers using Leterg do it to keep themselves anonymous.”

“Then it looks like you’ve got your work cut out for you,” Tomlinson said, and left.

Rainy picked up the CVIP report and read it again. Tomlinson was wrong about this one. These girls might have taken their pictures willingly, but that didn’t mean they weren’t in any danger.