A ding from the elevator brought Jo back to the present. She searched through the crowd and spotted Mac stepping off with his coat back on. She quickly grabbed her results, checked on the tests still running, and secured her evidence before following him. She waited outside his office until he sat at his desk and logged onto his computer, then she tapped on the glass door. The look on his face told her that he had been waiting for her to show up. He waved her in and she decided that he would probably appreciate it if she started with the evidence before the personal questions.

"Your hunch was right, Mac. The white substance that was transferred to the iPod case came back positive for cocaine. DNA is still running, but I think all the blood from the jacket will come back to the victim."

Mac took the results from Jo and looked over them. "It appears to be low grade cocaine, it's nowhere near being pure." He glanced up at Jo.

"Well, so far this is our only link to the shooter. Adam is examining the vic's clothes for trace but it looks to be a clean kill."

Mac smiled. "There's no such thing." He glanced back at the results. "Jordan mentioned that the shooter was shaking. She thought he was cold, but he may have been exhibiting withdrawal symptoms. The vic was wearing an expensive watch and overcoat. This may be a robbery gone wrong. That, added to the trace elements of cocaine," he handed the results back to Jo "suggests that we may be looking at a drug addict as our shooter."

"That's what I was thinking. I have Flack canvasing known drug dealers in the vicinity of the crime scene, looking for someone who maybe had some quick cash unexpectedly." Mac nodded and turned his attention to his computer. Since he had mentioned Jordan, she decided now was as good a time as any to broach the subject.

"Jordan seems to be a smart girl, especially considering how much she noticed about the shooter."

Mac nodded, but didn't look at her. "Yes, she's very observant. Notices little details that often get lost in the mix." Mac's scientific approach to people and emotions made Jo smile.

"Is she ok? She seemed a little shaken up, understandably so."

Mac finally glanced at her, with a look that said he knew she was fishing for information. "She was, a little. I gave her a ride home, she seemed calm." He regretted mentioning the ride when he saw Jo's eyes light up with curiosity. He gave her a look of fond exasperation. "Flack was going to take her home but he got called away. I had taken her jacket as evidence, it's freezing outside, and so…" he trailed off.

"So you took her home so she wouldn't have to walk."

"Yes, I did. That's all." Any hope he had of ending the conversation died when Jo gave him her 'I'm not buying it' look. She pulled up one of the chairs across from his desk and sat down. "Mac, tell me. Who is this girl? I know there's more to this story."

He smiled at her earnest expression. "I'm sure Danny filled you in."

"He told me that she was a witness in a murder investigation, that she was helpful in interpreting evidence."

She saw a glimmer of something darken the color in Mac's eyes. "She was beyond helpful, she was crucial to the investigation. We had evidence without context, no way of connecting it together. She knew the victim and she knew the crime scene. It turns out, she had seen the suspect several times before the murder and she had seen him running out of the building on the day the victim was killed."

Jo softened her voice in response to the obvious emotion Mac was feeling. "So what happened?"

Mac stared off past her. She watched the emotions cross his face as he obviously was reliving memories. Finally, he turned to face her, raw sadness set firmly in his eyes.

"Her boyfriend died."

Jo inhaled sharply as she made the connection to what Danny had told her.

"He was murdered a week before the case was set to go to trial. Jordan just…" He passed a hand over his face in a rough gesture. "Jordan broke down. She was grieving, not thinking clearly, and she refused to testify."

Jo waited for Mac to collect himself. It was obvious that this memory was painful for him, but it wasn't clear to her why it was. Perhaps it was "Did she cause the case to be dismissed?" Jo thought maybe he felt responsible for the suspect getting off.

Mac shook his head, staring off again with a distant expression. "Actually, no. The two crimes seemed to be related, the suspect was in custody for the second so it obviously wasn't him, and the DA didn't go forward with the case." He chuckled to himself. "It actually had nothing to do with Jordan."

"Mac what happened? She was barely speaking to you, she looked scared. Is there any reason she would be afraid of you?"

Mac gave her the same expression that Danny had. "She's not afraid of me."

Jo still wasn't convinced. "She's scared of something."

Mac stood up, obviously done with the conversation. "Right now, she's just another witness. She'll give her written statement to Flack, but we need to work the evidence. Have we managed to ID this guy yet?"

Jo sighed. She had pushed him too far, and although she had more to the puzzle, she felt as though she were missing a key piece. "Sid hasn't finished the autopsy, and Lindsay is running DNA as we speak. So far, he's still a John Doe."

Danny came through Mac's secondary office door as she spoke the last sentence. "Make that a John Dorin. Fingerprints came back on the vic, he has a record. He was arrested two times on aggravated assault and once on assault with a deadly weapon, but he was never convicted."

Jo turned back to Mac. "Arrested three times with no conviction? He certainly had a lucky streak."

Mac took the records from Danny. "Or a good lawyer."

Danny crossed his arms. "You thinkin' he's connected?"

Mac looked up at him. "Someone put time and effort into keeping this man out of prison."

"Ok, I'll run his name by the organized crime unit, see what I can find."

Mac nodded and Danny left the office. Jo stayed in place, staring at the door Danny had left by. Mac caught her thoughtful expression.

"What is it?"

Jo shook her head. "I'm just wondering, what is a well-dressed man with a possible mob connection doing in an alley behind an bookstore? And what is the drug connection?"

He nodded slowly. "We have possible motive for the shooter, but we still need to establish exactly what the victim was doing at the scene." He smiled at her. "You know what I'm going to say?"

Jo smiled back at him. "Follow the evidence?"

"You got it."

She nodded, gathered her results, and turned to leave. She paused at the door and faced Mac as he sat back at his desk.

"Mac?" She waited until he glanced up at her. "You know, if you ever need to talk…"

Mac smiled slightly. "I appreciate that, Jo."

She nodded and left his office. Her work was obviously cut out for her, both to find the shooter and figure out just what Jordan was so afraid of.