The Five Stages of Grief, otherwise known as the Kubler-Ross Model, is based on the book On Death and Dying by Dr. Elizabeth Kubler-Ross.

Denial

  GARCIA: I get it. We're a family and it's important that families 

  talk, and holding it in will just make this sick, sad feeling of 

  awfulness more awful. Right?

  HOTCH: Internalizing does make it worse.

  GARCIA: I'll talk, but I don't want to talk about her gone. Can 

  I talk about how she made me smile?

     

Bargaining

     MORGAN: 60 seconds. If I had just gotten there 60 seconds 

     earlier, Emily might still be with us.

     HOTCH: Derek, you know you did everything you could.

     MORGAN: Yeah, yeah. I know I did everything I could. We 

     all did. I know. But, is that supposed to make me feel better?

     HOTCH: You protected each other for years. Don't expect 

     this to go away anytime soon.

     MORGAN: This what - this what - this guilt?

     HOTCH: Just because you were the last one there, doesn't 

     mean you could have affected the outcome.

Anger

      MORGAN: Angry. Yeah. Yes. Sometimes I feel like I want to 

     quit my job and spending my time chasing down that son of 

     the bitch that killed Emily. You're damn right I am angry.

     

     (later) So what do we do - we just chalk it up to fate? I can't

     blame anybody - this is the will of God? No. I do blame 

     somebody. I blame Doyle.

      REID: It's just unfair that she is gone. It's like.. if we can't keep 

     each other safe, then why are we doing any of this?

Depression

REID: Sometimes I think maybe...maybe Gideon was 

right. Maybe, it's just not worth it.

    

Acceptance

Here, Rossi does not express the same sentiments as Garcia, Reid and Morgan do.
He seems more accepting that Emily's gone. 

    ROSSI: I've always had trouble letting people in. But this is 

    different. I guess, I've come to realize that I 'm more married to 

    this team than I ever was to 3 ex-wives.

    HOTCH: It's been a hard year. We'll get through this.

    ROSSI: Yeah, we will. (Raises drink) Emily and Haley.

On the other hand, Rossi does 'bargain' in a different sense. He gets to know about Hotch's own status in dealing with the aftermath of Haley's death and becoming a single parent, offers a little of his own thoughts, before reaching an agreement with Hotch over some scotch.