Body of Evidence

'That's it,' he said, nodding, 'that's gotta be it.'

At HQ, O'Riley led Randle into an interview room and Nick and Catherine marched back to the garage where Nunez had set up shop. Nick opened the door and saw Nunez poring over his monitor, Grissom-in black polo and slacks-standing just behind him.

'What's up, Gris?' Nick asked, trying to keep it light.

Their supervisor turned and smiled at them in an angelic fashion that chilled Nick's blood. 'Gee, Nick-that's just what I was going to ask you…'

'Hey,' Catherine said, quietly defensive. 'We were in the midst of a righteous arrest when somebody on this end got nervous. Why?'

Nunez appeared to be so hard at work he was neither hearing nor noticing what was happening nearby; Nick didn't buy it for a second.

Grissom folded his arms; his head bobbed to one side and his eyes were unnervingly placid. 'Tell me about the evidence you've developed for this case, Catherine…Nick.'

Nick and Catherine traded an uneasy look.

She had to be wondering, like he was wondering, just what the hell Grissom was so worked up about-though to anyone who didn't know him, Grissom's manner appeared calm, his two colleagues could feel the displeasure radiating off the seeming tranquillity.

'You,' Nick said to Catherine, who nodded, and laid out what they knew so far. Nick studied Grissom's implacable face, looking for evidence of what was going on behind the unblinking eyes, with no success.

'You found the laptop in Randle's house,' Grissom said, nodding once, then cocking his head again, lifting an eyebrow, 'but no fingerprints.'

'Yes.' Catherine shrugged. 'But that's not uncommon in cases like this.'

'True, but a predictable lack of evidence is not in fact evidence.'

She shrugged again, a little embarrassed. 'True,' she echoed.

Now both Grissom's eyebrows lifted. 'Did you wait for Tomas to finish his analysis before you ran off to arrest Mr. Randle?'

Gesturing toward the seemingly oblivious computer expert, Catherine said, 'Tomas hadn't even started on it-but he told us the scan showed that the pictures had been on the zip disk we found in Randle's office.'

Grissom turned toward Nunez. 'Tomas, would you care stop pretending you're working, and tell my CSIs what you did find?'

Looking at least as exhausted as O'Riley had-and as if he wished he were anywhere else-Nunez wheeled in his chair to face the trio, but his eyes went to Catherine. 'Catherine, remember I told you that the print order came from work station eighteen?'

'Yes.'

'Well, after we popped that bank hacker, I went back to it. There's no evidence that the photos originated from that computer.'

'Well, it did come from the zip disk, right?' she said, sounding a little less sure of herself.

Nunez nodded. 'That's true; but that's not the problem. I checked the MAC address of the NIC card.'

Shaking his head as if trying to dislodge an insect, Nick said, 'Whoa! I have no idea what you just said.'

Nunez took it slowly. 'The NIC or Network Interface Card is a piece of hardware inside each computer in Newcombe-Gold's office. It's what connects to the network cable and thus connects each computer to the network. Each NIC has a MAC or Media Access Control address that is unique to each machine. These MACs cannot be easily changed.'

'Oh-kay,' Nick said, glancing at Catherine, 'we're with you that far.'

'All right. Although information is routed by the IP address, that's the identifier I told Catherine about before…'

They both nodded.

'…even though information's routed with this IP, it's sent and delivered by the MAC address.'

'I think I need a couple aspirin,' Nick said.

Catherine added, 'I could use three.'

Grissom said, 'Layman's terms, Mr. Nunez.'

Nunez said, 'Think of the IP as the Post Office and the MAC as the mailman. Although the Post Office sorts the mail and makes sure it's all headed for the right box, the mailman delivers it. I found that the server log for the network showed the MAC address of the sending client computer to be this…'

He presented them with a sheet of notepad paper on which was written: '08:00:69:02:01:FC.'

Nick shrugged at Catherine; Catherine shrugged at Nick. Grissom closed his eyes.

Nunez kept trying: 'That MAC doesn't match up with the MAC address of the computer in work station eighteen, even though the IP matched.'

A sinking feeling came over Nick-he not only followed this, he had a terrible feeling he was not going to like what Nunez had to say next….

'The computer we thought sent the print order…didn't.'

Nick winced, then suggested, 'Maybe you put the wrong computer back in the work station.'

Nunez shook his head. 'No way-didn't happen. Besides, I had all the serial numbers from the original seizure of equipment.'

Head tilted, eyes narrowed, arms folded, Catherine asked, 'Just how were we fooled? Actually, Tomas…how were you fooled?'

Grinning ruefully, Nunez said, 'Helluva question, Catherine. And I don't have the whole answer, but I know where the answer starts: somebody wanted to fool us.'

Again Catherine and Nick traded glances, wide-eyed ones. Grissom's eyes, however, were still closed. Catherine asked, 'Who?'

'That,' Nunez said, 'I don't know…yet.'

Grissom's eyes opened and he said, 'He does know how…. Tell them, Mr. Nunez.'

Nunez presented them with a larger piece of paper, this time-with a rough drawing he'd made. 'This box represents the computer in eighteen.'

'Okay,' Nick said.

'This box,' he pointed to another square he'd sketched, 'is a computer hooked to the network that was supposed to spoof eighteen.'

'Spoof?' Catherine asked.

'Imitate. Simulate…And, from our being lost for so long, I'd say it worked. Anyway, the print order originated there.'

Feeling sick, Nick asked, 'Which leaves us where?'

Nunez sighed, sat back in his wheeled chair. 'I already checked the MAC addresses we had from Newcombe-Gold-it doesn't match any of their computers.'

Catherine's head lowered and she covered her face with a hand.

'Please tell me we're not back to square one,' Nick moaned.

'Not all the way back,' Nunez said, trying to minimize their woe. 'But when I couldn't find any trace of the photos on the network server hard drives, I ran an E-Script to carve out all the jpegs-since that's the most popular format of most kiddie pornographers. In unallocated space, I found the pictures angel1angel12.jpg. The reference file indicated that they had been accessed from the D drive-a zip disk. I ran the MD5 hash algorithm and noted the hash values of the pictures.'

Nick, who'd just been thinking he was actually following this, held up a 'stop' hand. 'Hash value?'

Nunez nodded. 'It's like a digital fingerprint. The value for Angel12 is…' He checked his notes: 'E283120A0B462DB00CEAFA353741F5E9. When we find another file with that hash value, we'll have our source material.'

'Near mathematical certainty,' Grissom said.

Nodding emphatically, Nunez said, 'It's like I told Catherine-the odds against two files having the same hash value and not being identical are astronomical.'

Catherine asked, 'Have you done the laptop we found at Randle's house yet?'