“Good question,” Rider replied. “I asked the O’Connors the same thing. They did some snooping around after getting into the server. They found a cookie jar on the web site. What that means is that there is a program that captures data about each user who enters the site. It then analyzes the data to determine if someone has entered the site who should not have had access. Even if they have the passwords, their entry is still recorded and a data trail called an Internet protocol address is left behind. It’s like fingerprints. The IP, or the cookie, is left on the site you enter. The cookie jar program will then analyze the IP address and match it to a list of known users. If there is no match a flag is raised. The site’s manager sees the flag and can trace the intruder. Or he can set up a tripwire program that waits for a return visit from the intruder. When he comes back, the program will attach a tracer which will provide the site manager with the intruder’s E-mail address. And once you have that you have the intruder cold. You can identify him then. If it looks like a cop you close the elevator — the page you hijacked and were using as a secret gateway — and you go find a new web page to hijack. But in this case it wasn’t a cop. It was a lawyer.”

“And they didn’t shut down,” Bosch said. “They sent someone out to kill him.”

“Right.”

“So you think this is what Elias did,” Bosch said. “He got these notes in the mail and followed the clues. He stumbled into this web site and set off an alarm. A flag. They then killed him.”

“Yes, that would be my interpretation of what we know at this point, particularly in light of the fourth note. ‘He knows you know.’ ”

Bosch shook his head, confused by his own extrapolations of the story.

“I’m still not getting this. Who is the ‘they’ we’re talking about here? That I just accused of murder.”

“The group. The users of the site. The site administrator — which might possibly be Kincaid — picked up on the intruder, realized it was Elias, and dispatched someone to take care of the problem in order to fend off exposure. Whether or not he polled all members of the group first doesn’t matter. They are all guilty because the web site is a criminal enterprise.”

Bosch held his hand up to slow her down.

“Slow down. We can leave the group and the bigger picture for the DA to worry about. Stay focused on the killer and Kincaid. We are assuming he was involved in all of this and somehow someone knew about it, then decided to inform Elias instead of the cops. Does that make sense?”