At first, they look like any other subway ad for a certain low-level New York lawyer: A middle-aged man, a cheesy font, a name — John Stone. Unless you noticed the HBO logo in the corner, you wouldn’t know it was promoting HBO’s limited series “The Night Of,” starring John Turturro as one of those low-level New York lawyers who takes on the case of a Pakistani-American college kid from Queens accused of murder (played by Riz Ahmed).

“The lady who works at our house, she was on the subway and saw it, and went to take a picture of it,” Turturro, who lives in Brooklyn, tells Variety. “A guy saw her and said, ‘Do you know that guy?’ She said, ‘Yeah, I work for him,’ and he said, ‘Is he a good lawyer?'”

John Stone was a good enough lawyer, though his client suffered possibly irreparable psychic damage from his time on Rikers Island. Turturro called up Variety in the middle of January to discuss the criminal justice system, whether we might be seeing more of his character on TV, and how being a lawyer and quantum physics are entangled.

There’s been talk of doing some more of “The Night Of,” following John Stone as he takes another case. Any updates?

We’ll see. They’re talking to Richard [Price] and Steven [Zaillan]. It really was their thing. It’s a great format. I’ve always been kind of afraid to hook onto something before, but I really loved working with Steve and Richard and the cast. If we could keep the quality up and it was about something, I’d do more.

This installment was very definitively about something. What did you learn about the criminal justice system you hadn’t known before?

If you’re accused of a crime and people are not ready to have a trial, they’ll delay, and it doesn’t count as time served — and if you can’t make bail you are really up the creek without a panel. I read this fantastic New Yorker article about Kalief Browder, and that actually stuck with me more than anything.

You’re in this area where things don’t make sense sometimes, and when it does, it’s kind of a miracle. People who do this are overworked, they don’t have money. A lot of people I met, they have these relationships and they all fall apart and they lose themselves to this other world.

What did you do for research for this?

I had done a lot of research years ago for “Clockers,” and a lot of it I’ve never ever forgotten. My role was cut down, but I remember all of the research, and it was unbelievably fascinating. I was with homicide detectives then; this time I was with lawyers. You go to crime scenes. I was always the “lucky” person with the homicide squad, there was someone dead when I was around. I saw a guy rob a gas station with a water pistol and then he was lying there bloated and dead and he had a water pistol in his hand. And the cops were making jokes, talk about black humor. That’s also important: how do people survive? How do you get certain things out of your brain, or even out of your nose? The crime scenes … the smell is what stays.

To be a good defense lawyer you have to control time and space — it’s a little like quantum physics. You have to present a reality. I talked a lot with a lawyer, Kenneth Montgomery, and he was telling me this — he’s the lawyer John Stone could have been. But it also has a cost. I’ve always been interested in these cases that are never solved, people are haunted by them, the cost of being involved in them. You see what it does to people. They could be a great lawyer, but they don’t want to deal with the potential consequences of having someone’s life in their hands.

How long did the eczema makeup for your feet take to put on?

I didn’t realize how time-consuming it would be — couple of hours. We looked at so many real cases. You have to really stretch out and you’re in there like a gynecologist’s office. I kind of liked walking around like that, though it was cold. People either stared at it or looked away ’cause it looked real; I looked like an animal. People come up to me all the time, they think it’s real: “How’s the feet?” they ask.

The people who actually have it go out of their minds, they can’t sleep, they’re in pain, they try everything. I just thought it was part of the guy, what he does comes out of his body, it’s part of who he is. It’s another problem he has to deal with.