You were a police officer in Washington D.C.  Your older sister, Emily, was apart of the BAU. You had called her asking about one of your cases. Every single Wednesday, a woman is reported missing. It's like clock work. They all have y/h/c hair and y/e/c eyes. You've been trying to find them but there are no leads. Dead ends, all of them.

Fifteen women. Fifteen. And you can't find a single one of them.

Then there was a break in the case.

Someone found one of their bodies. They had been digging to plant a tree and found the body all wrapped up.

The body was of the suspected eighth victim, Rebecca Morris. Her clothes had been changed. Her arms were crossed. She had bandaids over her. She had been stabbed in the heart.

After she was found, you expressed your concern to your boss, the police captain. Luckily for you, he shared the same concern and invited the BAU in.

The BAU took the case and was down at the station in an hour.

Once you saw your sister, you hugged and her and thanked her for coming.

You faced the rest of the team, "I'm Detective Prentiss but you can just call me Y/n"

JJ told her friend, "I didn't know you had a sister"

Your sister said, "Well I do and I still think Agent Prentiss still sounds better than Detective Prentiss"

"Oh wow, thanks a lot"

Your eyes shifted to the tall and lanky agent with the shaggy hair you knew must be Dr. Spencer Reid. Your sister never mentioned how hot he was. She said Morgan got a lot of action and that Spencer definitely did not. You didn't expect the doctor to be so handsome.

"You must be Dr. Reid, Morgan, Rossi, Hotch and JJ" you said pointing to the person as you said their name.

"That was spot on. How'd you know all of our names?" asked Reid.

"Emily talks"

"Good things I hope" remarked Rossi.

Hotch told his team, "Reid and Prentiss, I need you to go to where the body was found. Morgan and Rossi, you two go to the morgue"

You turned to your sister and took your gaze off the doctor, "I can take you"

"Good" your sister told you.

You took your sister and the hot doctor to where the body was found. It was found on a ranch on the border of DC. The owners were planting some trees when they dug and found the body on the border of their property.

Emily said, "Well he clearly didn't want it to be found"

"He buried them six feet under like a grave" Reid pointed out.

Emily and Reid asked the owners about the condition of the body. It was wrapped in a blanket and the arms were crossed, a classic sign of remorse. They hadn't seen any strange cars or people.

You got a call from the police captain. Someone found another body. This time, it was of the fourteenth victim, Ramona Quinn. She went missing last Tuesday. Her body was found in Maryland, right out side of DC.

It was lucky you guys were notified of that. You had a friend from the Police Academy and that body was found in her jurisdiction. You told her about the case.

You announced, "Guys, someone found another body, Ramona Quinn in Maryland"

"Let's go" said Emily.

You took Emily and Reid to Maryland to where the body was. You met up with your friend, Kyrsten Trainor. She was exceptionally unique. Her eyes were two different colors, one brown and the other green.

You told your friend, "Thank you for telling us about this"

"You're lucky we're friends, Prentiss" remarked Kyrsten.

"I sure am"

"Is Cameron still in love with you?"

Cameron was a CSI you worked with quite a lot. Every single Tuesday, he reminded you that he was available and was in love with you. At first you thought it was a prank but then you realized he was telling then truth. You let him gently and you've been doing it for the past fifteen weeks.

You replied to your friend,'"Yeah. He reminds me every Tuesday. God, I wish he could just take the hint"

Emily and Reid came over after inspecting the body. They told you some details. The M.O. was the same. Stabbed once in the heart, defensive wounds that were cleaned up, wrapped in a blanket and same victimology. The only difference was the body wasn't found six feet under. She was found in a dumpster by someone taking out the trash.

Another odd thing was that he left a note written in her blood, I left her for her.

Who was this second her?

Emily said, "She died less than twenty four hours ago but she's been missing for a week"

"So he keeps them alive before killing them" pointed out Dr. Reid.

You found some relief. This mean that the last missing women, Monica Green, was still alive.

"But why keep them alive?" asked Emily.

You suggested, "Sex maybe?"

"There are no signs of sexual assault left on the bodies" said Reid.

"He bandaged their wounds and changed their bloody clothes. What if cleaned the bodies to get rid of any sign of sexual assault?" suggested your sister.

You told them, "That would require lab equipment and knowledge that someone on the force would have"

"Like a CSI?" suggest Reid.

You remarked back, "Technically we're all allowed in the crime lab. The CSI are just the only ones that work there. Anyone on the force could just steal some of the supplies"

Emily said, "We need to get a profile out fast"

You guys headed back to the station. Yo watched the BAU scramble to get a profile together. He sued the women as a surrogate. There was only a matter of time before he went after the real deal. The thing that was the most concerning was the possibility he could be a cop.

SPENCER'S POV

One thing I noticed about Y/n was that she kept looking at me. I couldn't figure out why. I knew we were trying to put together a profile but I couldn't get Prentiss's sister out of my head.

"Why does she keep looking at me?" I asked out loud to no one in specific.

Morgan asked, "Who?"

"Prentiss's sister, it's weird" I told him.

"Dude! She's checking you out"

"What? No, she's not"

Apparently Prentiss overheard us, "Trust me she is. You're her type. Handsome, nerdy, smart, responsible. Her taste in guys is a lot better than mine"

...

I did not how to react to that.

"You know I can give you her number" Prentiss told me.

I said, "I actually would like that, thank you very much"

Did I just thank Prentiss for giving me her sister's phone number?

We got ready and gave the profile out. Strange, I didn't see Y/n there. She should've been there.

Her partner came up to us after the profile. He asked Prentiss if she had seen her around in the past fifteen minutes.

"What do you mean you don't know where she is? She's your partner!" yelled Prentiss.

Her partner, Eddie Thane, said, "I didn't even know she had a sister until you came here"

Then I got an idea, "Her, I left her for her. What if Y/n's the her in the message? She fits the victimology. What if she's the one our unsub is 'in love' with?"

Eddie said, "Ryan Cameron, he's a CSI who is in love with Y/n and he fits the profile"

Prentiss seemed upset that she didn't know about Cameron. We were able to get his address pretty quick.

We barged in, Morgan kicked down the doors. The first level was clear. Morgan and Eddie headed upstairs while Prentiss and I went down to the basement.

We found Ryan Cameron and Y/n all tied up. Ryan was holding a bloody knife with latex gloves on.

Prentiss pointed her gun at Cameron, "Put the knife down!"

Cameron dropped the knife, "I wasn't going to hurt her. I would never hurt her"

Prentiss arrested Cameron while I went over to Y/n and untied her. Monica Green was not in the basement. I asked her if she saw her but she said no. Prentiss dragged Cameron upstairs leaving me alone with her hot sister.

I bagged the bloody knife for evidence and looked around for more evidence. I found some more evidence. He recorded the rapes. The tapes were label. There were over fifteen tapes but only fifteen names.

Abbigail Gates

Bree LaRoss

Sarah Davenport

Katie Raymond

Alex Rose

Daisy Jones

Kiera Smith

Rebecca Morris

Lorelei Holden

Paris Gilmore

Amber Beckett

Kathy Moore

Phoebe Miller

Ramona Quinn

Monica Green

Those are all the names of the victims Y/n had suspected. I bagged all the tapes as well.

Y/n was unharmed and unarmed. She found her gun and took it back.

Morgan and Eddie found Monica Green upstairs, barely alive. Her arms were all cut up.

We went back to the station and Cameron confessed. He also told us where to find the rest of the bodies.

YOUR POV

Cameron... you couldn't believe. That sweet CSI was a killer, a delusional serial killer who loved you.

You were with your sister down at the station. You had a blanket around you. It was comforting like a hug. You didn't notice you were checking out the hot doctor again.

Emily told you, "I gave him your number"

"What? Who did you give my number out to?" you asked.

She pointed to the hot doctor, "Reid. You keep checking him out like you're doing right now"

"He is hot"

"I think you're about the only person who thinks that. I also think you two would make quite the cute couple"

You smacked your sister's arm, "Emily!"

"What? You and I both know it's true"

Okay she was right about that but still. You didn't need your sister to get a boyfriend. You have had few boyfriends in the past that you didn't get a date with from help with your sister.

You told her, "You know I don't need my big sister setting me up anymore. I am fully capable of getting myself a date"

"But you don't mind my help do you?" asked your sister.

"Okay fine, this time your help was actually appreciated"

After the case was all done and settled, Reid called you up and asked you on a date. You were pretty sure he was reading off a script when he did so. You said yes obviously.

You thought the date might be awkward because you were Emily's little sister after all but it wasn't. He took you out to dinner and you had a great time. He kissed you goodnight and you told him that you should do this again some time.

A/N: I don't think I've ever read a one shot where you were Emily's sister. I was thinking if maybe doing a part two to broken and maybe a part to Atlantic City. I also have an idea for one where you are Strauss's Daughter. Tell me what you think in the comments.