SPOILER ALERT: Do not read if you have not yet watched the second season of “Criminal: U.K.,” streaming on Netflix.

George Kay and Jim Field Smith created and premiered the “Criminal” franchise (four unique series across four different territories: the U.K., France, Germany and Spain) with a storytelling focus on a “did the guy do it or not?” traditional dramatic police premise, notes Kay. But at the heart of their inspiration for the series was creating “stories that made the police have to face their own morality and explore how they feel, not just what they do for a job,” he continues. The second season of “Criminal: U.K.,” streaming on Netflix almost exactly one year after Season 1, allows them such an evolution.

“We’re not interested in black or white guilt or innocence. We’re interested in, even if the character is charged with a crime, is that the right outcome? Just because something is legally correct, is it morally correct?” Smith tells Variety. “The fun of the show is in the audience being a sort of jury. We want that ebb and flow of guilt and innocence.”

The four-episode second season follows detectives as they interview a variety of citizens — from a woman at first only being treated as a supporting witness in a murder case (Sophie Okonedo), to a man accused of rape (Kit Harington), an online vigilante (Sharon Horgan) who outed a man she was led to believe was a pedophile, and an already-convicted criminal (Kunal Nayyar) who is looking to strike a deal in exchange for information about an unsolved missing child case.

Two of these four characters (Okonedo’s and Nayyar’s) confess to crimes by the end of their episodes, while Horgan’s character’s behavior is determined to be reckless enough to bring a case against her to court, despite her good intentions. Harington’s character is the lone one who appears to be innocent of the crime of which he is charged after his accuser is found not fully credible.

“Sophie’s episode, yes she’s a criminal, but her husband’s treatment of their marriage, there’s a crime there that we were really interested in exploring. The moral crime, perhaps, is the betrayal of the marriage by the husband, so what’s technically crime and what’s underneath it all is what we wanted to explore,” Kay says. “We’re constantly trying to put a mirror up to everything — literally. It’s important to represent all aspects of all crimes that come the way of the police.”

In the case of Harington’s character, who Smith calls “an archetype” that British viewers would have an “innate bias” against, Kay adds, “I also think it’s a tough thing for a person innocent of those charges to have to go back to a normal life. There’s a smell around that, even if we don’t like him very much.”

In crafting Harington’s episode, Kay notes one of the first things that interested him was how physical evidence is considered in the U.K. “A lack of bruising or physical evidence in a case like that should not be taken as a suggestion of a lack of a rape having happened, and at the same time, physical bruising or evidence should not be seen as indicative of a rape either,” he explains. “I found that fascinating because it leaves the police in a complete no man’s land where evidence is taken away from them for the safety of getting it wrong — but at the same time they’re at the risk of not pressing charges when perhaps they should have. The whole ambition [of that episode] was to write about those cases in the U.K. — and I think it should apply in other countries — where whether or not the allegation is real, there’s a sense in the process where nobody wins.”

Therefore, it has been just as important to spotlight the detectives and the overall criminal justice system in the second season.

Research into police approach in the U.K. revealed that caution comes first, Smith says. “The British police have to work very, very carefully to build a case. It’s very much one of treating the suspects almost as a client — as someone they’re working with to build the best possible case to be able to take to court. The justice system in the U.K. is set up so the police really have to have done an extensive amount of homework, it’s quite non-prosecutorial in that sense [and] it leads to quite a non-adversarial interview technique, and we try to reflect that in the show.”

That is, in part, why detectives allow Harington’s character to deliver what is essentially a monologue, not only telling his version of events on the night of the alleged assault, but also after he learns he is being let go and is worried about those in his life not believing he is innocent, even though charges didn’t stick. It is also what leads Okonedo’s character to ultimately incriminate herself while being interviewed.

Initially, Vanessa Warren (Rochenda Sandall), who is interviewing Okonedo’s character, doesn’t catch her slip-up, but another member of the police, watching their discussion on monitors, does. As the interview continues, others are able to work behind the scenes to look at the case from this new angle, then follow up with new interview questions.

“Policemen and women are not superheroes. They’re just people like you or I. Many of them do an astonishing job — not all of them. But very many of them want to do the best job and they don’t always know how to do that,” Smith says. “Something George said early on was, ‘Well, who is on which side of the table? Who is really under investigation — under scrutiny — here?'”

Whether that means a “Criminal: U.S.” may be forthcoming still remains to be seen, though. “There’s so many interesting things going on in America with what is dividing society and moral questions about how Americans are living their lives. It’s just about placing society up against itself. You want to be faithful to the police techniques of the country in the version of the show,” says Kay.

In the meantime, looking at the fallibility of humans in general in “Criminal: U.K.” Season 2 allowed for fallout, or at least disappointment, for characters on both sides of the table — and the audience by extension. There is a bit of a runner with the character of Petit (Shubham Saraf) trying to toss balled up paper into a garbage basket, and at the end of Harington’s episode, “he misses — because the whole thing is one big mess,” Kay points out.

Additionally, Warren ends up getting her confession and being told she can move up the ranks at work results in her saying she doesn’t want to because she wants a solid work-life balance. “I’ve long wanted to write about what is expected in terms of ambition for a woman in the workplace,” Kay says, calling that scene one of his “proudest pieces” of the second season. “I’m really interested in how we interact in the workplace.”