Mac and Stella went back to the lab and were soon approached by Lindsey with a smile on her face.

" Your look says you have good news," Stella said.

" That depends. Hawkes and I talked to Clarissa Wallace and she gave me the sweater she was wearing the night Ethan Crowley was found. The fiber that was in the car is a match to the sweater."

" We know however that Clarissa had emergency surgery that night," Mac said," Reports confirm it. Did she tell you anything else?"

" Only that she still can't figure out who would want Ethan dead. There's not much to go on here."

Mac then went into his office and sat down.

" Something troubling you Mac?" Stella asked.

" Staci Collins and Emily McKenzie claimed to be together the other night, but Staci was up on that roof just a few hours later."

" You still think she's hiding something?"

There was a knock on the door and Danny came in.

" I just processed the gun that Staci Collins had, it was empty. I ran the gun through the system and it came up to a Richard Collins, her father. The bad news though, Richard Collins died in a car accident last year on the New Jersey Turnpike."

Mac shook his head.

" That's what Staci's mother told me," Mac said," So who else wanted Ethan dead?"

In the meantime, Flack went to go talk to Alex Crenshaw, but go no answer at the apartment. Flack was about to leave when he turned around and saw someone.

" May I help you?" the young lady asked.

" Detective Flack, NYPD. I'm looking for Alex Crenshaw."

" He's work. I'm Joelle. Is this about Ethan?"

Flack only nodded his head. Joelle opened the door.

" Come in. Maybe I can help you."

" How well did you know Ethan?"

Joelle shut the door.

" As well as I could. I don't know what else to say."

" Do you know an Emily McKenzie?"

Joelle sighed and nodded her head.

" Emily and Ethan used to go out, but then they broke up and I really don't want to talk about why."

" Did Alex have anything against Ethan?"

" No. They were best friends. Why are the same questions being asked? Alex didn't kill Ethan. Emily, she might've. In fact I saw her the night Ethan was killed."

" Where?"

" Just out walking. She said she was going back home to study."

" Was she alone?"

Joelle just nodded her head.

" Thank you for your time."

Flack left that apartment and immediately called Mac.

" Mac, we need to bring Emily McKenzie back in either her, Staci Collins, or both of them are lying about where they were."

It was about an hour later when, Mac and Flack showed up at Staci's apartment. The door was answered by Katherine, who seemed highly upset.

" Mrs. Collins? Mac asked," We need to talk to Staci."

" I don't know where she is. She's gone. All she left was this note."

Katherine handed the note to Mac.

" Mom, I can't take this anymore. I need to go somewhere I feel safe. I don't feel safe here anymore."

" She's left Flack. Do you know where she would go?"

Katherine shook her head.

" I'm not sure. I've been trying to figure that out. The one place she felt the most comfortable was when she was with her father. Her father? The cemetery. I know this doesn't sound good, but my daughter isn't a killer."

" I'm sorry Mrs. Collins when we find Staci, she's being taken back into custody," Mac told her," This time she won't come home right away."

" Then I'm going to call my lawyer. My husband was a lawyer. Staci won't fight you."

Mac and Flack left the apartment.

" The alibi's aren't so solid afterall," Flack said," They made them up."

Meanwhile, Emily was standing outside Staci's apartment and saw the detectives leave.

" You're not going to find out the truth," Emily thought," You'll never discover who killed Ethan. You don't want to believe what you heard then I have to take desperate measures."

Emily turned around and looked right at Alex and Joelle.

" What the hell do you two want?"

" We know you did it," Alex said," Now we need to prove it."

" You won't prove anything."

" What are you doing lurking outside of Staci's apartment?" Joelle asked.

" Protecting her. You two sure wouldn't. What are you doing here?"

Joelle and Alex looked at her.

" You did do it," Joelle said," You killed Ethan."

" I didn't say that and you two have a motive to kill Ethan too. You'd better not mess with me. If you do, you'll be sorry."

Emily walked away.

" What do we do Alex? I wouldn't put past Emily to kill Ethan. You know how manipulating she can be."

" I know and we did see her that night. Nobody else was with her."

Joelle sighed. She didn't want to believe that Emily was a killer, but it was probably the truth.

In the meantime, Staci stood outside one of the biggest cemetery's in New York. Tears were forming in her eyes. She didn't notice that Mac had driven up and saw her.

" Staci Collins."

Staci ended up looking at him and a few moments later Flack showed up.

" You need to come with us," Mac told her," There's more questions to answer."

Staci looked at both of them.

" I was here that night. I stand outside these gates, but I can't go in. I miss my father, but it's not an excuse to lie to the police. I wasn't with Staci. I went along with her plan. I have no one to back me up. There were people that walked by, but they don't know me."

" What plan? Flack asked.

" I don't know. I asked her and she told me to trust her, so I did. Look where it's gotten me, a one way ticket back to the precinct. Why didn't I just tell you when I had the chance? What's the penalty for lying to the cops? I lied to protect my own skin. I didn't know what else to do. I wouldn't and didn't kill Ethan."

Mac just took her to the waiting car.

" Now we need to find Emily," Mac said," We're going to find out what her plan was."