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Mac Is a Serial Killer 

After reading that a serial killer is on the loose, the gang notices that Mac is acting shady and decides to find out if he's the man behind the murders.


Jerry Levine


Rob McElhenney (developer), Glenn Howerton (developer) | 3 more credits »




Episode credited cast:
Charlie Day ... Charlie Kelly
Glenn Howerton ... Dennis Reynolds
Rob McElhenney ... Mac
Kaitlin Olson ... Dee Reynolds
Danny DeVito ... Frank Reynolds
Mary Elizabeth Ellis ... Waitress
Brittany Daniel ... Carmen
Marcuis Harris ... Pimp
Rest of cast listed alphabetically:
Bill Chott ... Gary
Sandy Martin ... Mac's Mom


When a serial killer is loose in Philadelphia who targets blonde white women, the gang all tries to figure it out. So Dennis and Dee notice that Mac is visiting an unknown apartment everyday and suspect it to be him. So they decide to find out who the serial killer is by doing various experiments. Written by James Hake

Plot Summary | Add Synopsis





Parents Guide:

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Did You Know?


The knife Big Pimp Daddy pulls on Dennis is a Kershaw Leek. See more »


Dee Reynolds: Did you bring the condoms?
Mac: Ooooh. Not a fan of the whole condom thing.
See more »


References Law & Order (1990) See more »


Take a Letter to Miss Jones
Music by The Jack Gray Orchestra
See more »

User Reviews

15 January 2020 | by dougmacdonaldburrSee all my reviews

This is the best episode of the show ever. I have seen every episode and this is the best. There are a lot of great episodes to choose from, but, I think this really is the definitive episode of It's Always Sunny In Philadelphia. If you are trying to introduce someone to the show it is a great one to choose. It showcases every character at their very best. We see Dennis be a total psycho, Mac be sexually confused, Charlie as a charming fool, Dee as annoying, and Frank as a scumbag. The scene with Pepper Jack is especially hilarious. This showcases everything great about Sunny. The show has famously been described as Seinfeld on crack. Episodes like this are exactly why.

7 of 9 people found this review helpful.  Was this review helpful to you? | Report this
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Release Date:

18 October 2007 (USA) See more »

Company Credits

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Technical Specs


Aspect Ratio:

4:3 Full Frame
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