A/V Lab…15 minutes later…

"Adam, tell me you got something," Mac said. He was alone as he walked in to the A/V Lab.

"I got a plate number on the Cadillac that left the gas station after you got away, and it led me to a name," Adam said as he pulled up his results.

"Aaron Tracker?" Mac asked, looking at the screen in front of him.

"Priors for assault, drug dealing, possession, and I got a case that you worked on in his history as well," Adam said, pulling up the case from the database.

Mac nodded, "He was my prime suspect in the murder of Abigail Hernandez," Mac said, taking a seat in the nearest chair he could find.

Adam looked at him, "So…what are you thinking, boss?" Mac had on that look that Adam had seen before. Something was on Mac's mind and from the look on his face, it was troubling him.

"Aaron Tracker got away," Mac said. "I wasn't able to complete that case for a lack of evidence proving anyone's guilt. Aaron Tracker told me something that night I left him leave the precinct," Mac explained.

Adam nodded and looked at him. "What'd he tell you?"

Mac looked over at Adam. "He said, 'Watch your back'."

Stella walked with Mac as they headed to see Sid down in Autopsy. "So you're saying that Aaron Tracker is involved?"

"Yes, and I'm saying that this could possibly be a follow up on what he told me that night I let him walk," Mac said. He was clearly more than upset by that. "I knew he was the guy who did it, but I had no evidence to prove he was even there!"

Stella nodded. "Watch your back?"

"He believed by arresting him on so little evidence, we were wrong to arrest him in the first place. That's what he said anyways," Mac said with a frustrated sigh.

The two of them then walked in to Autopsy and Sid looked up at them. "I got your call and I pulled Abigail Hernandez's autopsy reports," he said as Mac and Stella joined him at one of the tables in the room. Laid out on the table were photographs, tox panel results, and other things from the full autopsy report. "If you don't mind my asking, why are we suddenly interested in this case again?" Sid asked.

"I think he was involved in attacking me last night and cutting my fuel line," Mac replied as he looked at the autopsy results and tox panel.

Sid nodded. "How's he involved?"

"Adam managed to pull a plate off the Cadillac the men had. The truck belongs to him," Mac said.

Sid looked at him. "Then I suggest you be careful, Mac."

Mac looked at him and Stella watched as the two of them shared a knowing look. "Why do you say that?"

Mac sighed and laid the reports back on the table and walked away as Sid watched him with sympathetic eyes. "Abigail's case hit him hard. She was only 15 years old and he had no evidence to prove who killed her. Her mother was heartbroken. Mac told her himself that she was murdered and later went back to tell her that he couldn't prove who killed her. It took its toll on him," Sid told Stella.

Stella nodded and looked followed Sid's gaze to look at Mac. "This second round of this guy isn't going to be any easier."

Sid nodded. "I'm just hoping this time we don't have to worry about him coming back."

Mac had stood alone for a moment, his mind going back to that winter day when he had to tell Debbie Hernandez that her daughter had been brutally murdered. He also remembered the day he went back and told her he hadn't found enough to prove who killed her daughter. Debbie had not been angry at Mac. In fact, Mac had been the one standing there as she cried. He had been her shoulder to cry on. To this day, Mac had no idea why he had.

Now Mac just figured he'd done it because he knew the pain of loss with no closure. He'd lost Claire, and today, he still didn't know if he'd ever have closure. That kind of pain can only be understood by people who know it. At least, it seemed to be that way.

Debbie had lost her husband just two years earlier. Then she'd lost her daughter. Mac staid with her for that night. They'd talked. They'd shared experiences.

Most of all, they talked about loss. They talked about the pain of losing those closest to you. Mac had talked about Claire. Debbie had told him about her husband. It was a night Mac knew he would never forget.

He sighed and started for the lab. He needed a lead on this case. He needed to get rid of the feeling someone was watching him at all times, the feeling that someone was prying their way in to his life with the intention of making it a living hell.

He needed to find out who else was involved. He needed to find out why.