We learn that the use of a blindfold is likely to mean one of two things: the unsub is unsure of killing and initially blindfolds the victim to avoid detection or it suggests the unsub feels remorse and doesn't want the victim to look at him as he kills.

Reid: It's possible our unsub is sort've a serial killer groupie.
Cop: So, is this guy an ex-con or some nutjob with an Amazon account?

Reid: An unsub's signature is his own extremely rare combination of MO and ritual. An unsub kills to satisfy an inner need, he'll continue killing until that inner need, which is based on a ritual, is lived out perfectly because reality never lives up to fantasy, this becomes an impossibility.
Gideon: In other words, he's not gonna stop killing until we catch him.

Elle: You guys, we're here in New York and even when we're not talking about our case we end up talking about another profiler.
Hotch: You're right. So, Elle... are you seeing anyone?

JJ: (to Reid struggling with his rubber band-aided chopsticks) How's it going there?
Reid: Awesome.

Reid: (on chopsticks) It's absolutely incredible, 1.3 billion people stay nourished using these things.

Morgan: Do I sense a but?
Garcia: Small but.
Morgan: That's not what I was jonesing for!

Lance Wagner: So, what happened? You get your men killed on the job and you think everybody else must be a killer, too?
Hotch: Watch your mouth!

Gideon: W.H. Auden said: "Murder is unique in that it abolishes the party it injures, so that society must take the place of the victim and on his behalf demand atonement or grant forgiveness."

Elle: This is not how I planned to spend a few days home in New York.
JJ: I'd kill for an afternoon at Barney's and dinner at Il Cantinori.
Reid: I'm looking forward to seeing New York.
Morgan: You've never been to New York?
Reid: We've never had an unsub there.
Hotch: (to Gideon) I thought you were going to talk to Reid about taking some vacation time.
Gideon: What's vacation time?

Hotch: You're a genius.
Garcia: You're just saying that 'cause it's true.

Reid: (having no luck with chopsticks) Excuse me, could I get a fork, perhaps? (to the BAU team) Did you know that experts credit Confucius with the advent of the chopstick? He equated knives with acts of aggression.
Morgan: (laughing) You don't know how to use them, do you?
Reid: It's like trying to forage for dinner with a pair of no. 2 pencils!

Hotch: (reading from the newspaper) Some day a real rain will come and wash all the scum off the streets.

Reid: (on the public's response to the unsub) The exact same thing happened with the Goetz New York subway shootings in the early eighties.
Gideon: You weren't even born.
Reid: I read a lot.

Gideon: Gandhi said: "Better to be violent if there's violence in our hearts then to put on the cloak of non-violence to cover impotence."
Hotch: Gandhi also said: "I object to violence because when it appears to do good, the good is only temporary. The evil it does, is permanent."

Reid tells the court officer that he's 24, but Gideon says that when the Goetz subway shootings occurred Reid wasn't born yet. The Goetz shootings occurred on December 22, 1984 -- 22 years ago. Either Reid's lying about his age, or Gideon's got his dates mixed up.

Reid: Did you know the original Zodiac Killer actually continually changed his victims - young, old, men, women, white, black.
Gideon: Exactly. And he killed for thirty years without ever being caught.

The Zodiac Killer is a serial killer who claims to have murdered 37 victims in his five years of terrorising the San Francisco Bay area but only 7 victims were linked back to him. In April, 2004, the San Francisco Police Department closed the case despite never uncovering the killer's identity.

Hotch: If this guy's who we think he is, we're talking terror like New York hasn't seen since Son of Sam.

Son of Sam, real name David Richard Berkowitz, was born in Brooklyn, New York. He is a serial killer who murdered six people and injured many others in the late 1970s.

Gideon: I'm worried about this guy becoming another Son of Sam. Then we might be dealing with a vigilante folk hero like Bernard Goetz.

Bernard Goetz was the victim of two muggings in New York which prompted him to carry a gun. On December 22, 1984, Goetz boarded a subway train and shortly afterwards was approached by four aggressive men demanding money. Feeling threatened, Goetz discharged his weapon using the 'speed shooting' defensive technique. He became a hero to the people of New York in a time of high crime rates.