Q. What is it supposed to be on the show?

A. An alleyway.

Q. Where is it supposed to be on the show?

A.  In New York City.

 
Q. When did we see it on the show?

A. In Episode 8 of Season One of Resurrection.

exter had prepared a kill room in the wig shop, where he planned to kill Al, the .“Rapunzel” killer.

But when he misses that opportunity, he decides to use the room to deal with another problem.




During an earlier meal in the theater district, Harrison had told Dexter about Elsa's miserable landlord, Vinny Valente, who had turned off her heat and refused to do anything about black mold in her apartment. After exhausting all of her options, Elsa was on the verge of being thrown out on the street.

In this scene, we see Vinny walking down the street, when he turns into a dark alley, while drinking a beer.  Dexter, wearing a stocking mask (since he plans to let Vinny survive this encounter), ambushes him, knocks him out with his M99 hypodermic, and takes him to the wig store's kill room, where he proceeds to scare him straight in a way that only Dexter can.  
 

In a funny moment, a guy goes walking right past Dexter in the alley during this assault. Dexter is alarmed, but the guy is focused on his phone, and with earphones on, he doesn't appear to have even noticed Dexter, who is standing just 3 feet away, and still wearing the stocking mask. Dexter is amazed, but then realizes that it's just part of New York's infamous street culture, where no one makes eye contact, and no one gets involved. He thinks to himself: “I love New York”. 

A. While the wig store is located near Greenwich Village, they shot this abduction scene a long way from there. 

They went back to Yonkers again, the city where their studio is based, and where they have shot many minor scenes before.

They shot this scene between 4 and 8 Undercliff Street, in Yonkers, New York.


The GPS coordinates are roughly: 40°55'30.7"N 73°53'41.5"W .

The building with the “MECHANIC” sign painted on wall is at: 8 Undercliff St.
 
It appears that Dexter pulls Vinny into a space between that Mechanic garage and a residential house/daycare center at 4 Undercliff St.
 
In the shots where the camera is looking out towards the street (as Vinny takes a swig from a bottle), the  camera is looking west, towards Broadway (US–9).


This location is only a few blocks north of the shopping center where they filmed that scene with Quinn at a Miami crime scene, and it's about a mile south of their studio and the other locations clustered around it.
 
Here is a matching StreetView of : 
 

 
Here is an aerial photo of the location.  And here is a map link.