Skip Kite admits he has been to some dark places in the last couple of years. Researching his film about the Yorkshire Ripper has seen him trawling through reel after reel of news footage, quizzing those who were involved in the long drawn out investigation and combing the forensic reports compiled after each murder.
By the time Peter Sutcliffe was arrested in the January of 1981, there were 13 murdered women on the files of West Yorkshire Police and 13 families struggling to come to terms with their role in the five year murder spree.
"The forensic reports were the worst," says Spike, who shot Peter: A Study for a Portrait of a Serial Killer on location in and around Bradford. "The details of how these women were killed were laid bare in black and white. They were necessarily written in a very clinical style. There was no emotion, just facts and somehow that made it even more chilling.
"I've been to a lot of dark places making this film, but it was important to me that I gathered as much information as I could."
The film is now finished and its completion couldn't have been better timed. Sutcliffe, who was sent to Broadmoor secure hospital in 1983 after being diagnosed with paranoid schizophrenia, has challenged the legality of his sentence and this week his attempt to have his whole life tariff over-turned reached the Court of Appeal.
His solicitors accept Sutcliffe's killing of 13 women and the attempted murders of a further seven were among the most brutal of crimes. However, they also insist that because of his obvious mental health issues, the original trial judge should have passed a long, but finite sentence instead of denying him the prospect of ever being released.
Three Court of Appeal judges this week reserved their decision, leaving Sutcliffe and the rest of the world to wait to hear if the application has been successful.
However, with the mere mention of Sutcliffe's name enough to open old wounds among those touched by his crimes, Kite says it is timely to remember the shadow which the former lorry driver cast over not just West Yorkshire, but the whole of the country.
"Next year it will be 30 years since the Yorkshire Ripper's arrest and trial," he says. "A lot of water has passed under the bridge, but with the case being again put before a judge, I hope my film will be a good reminder of the horrific crimes he carried out. Thirteen women died because of him and their bodies were mutilated in the most unimaginable way.
"The decision of whether Sutcliffe will ever have leave to apply for parole rests with the Court of Appeal and that's absolutely how it should be, but we must never ever forget what he did.
"Recently I went to the concentration camp at Belsen to make a film with some of the Holocaust survivors. One of them turned to me and said people should never feel sympathy for those who carry out terrible crimes, even when they become old, ill and infirm. She said we had to remember that when they committed the horrific acts they were young, fit and healthy.
"She was right and I guess that's how I feel about the Yorkshire Ripper."
While endless documentaries have been made about Sutcliffe and countless books have attempted to delve into the mind of the serial killer, Kite's will be the first feature film to be released.
"If I had pitched the idea to a studio for a film focusing on a serial killer, who as a teenager had got a job as a grave digger, who met the love of his life on Valentine's Day and who developed an obsession with prostitutes they would have accused me of being hackneyed," he says. "They would have been right, but Sutcliffe's story is full of of these quirks. Truth is so often stranger than fiction."
The film exposes Sutcliffe's warped views of women, but Kite says he was conscious the finished movie should be one he would be happy for the victims' families to watch. "There are no violent scenes, no blood and gore," he says. "To film a shopping list of murders would have been easy, but I was more interested in what was going on in Sutcliffe's mind, what turned him into a killer."
Richard McCann, whose mother Wilma was Sutcliffe's first victim was among the first to watch the film and he's now given his backing to the project.
"That meant so much," says Kite. "He'd had a bad experience with one documentary he had contributed to and he was understandably nervous about what we were doing.
"However, I assured him right from the start that while it was inevitably going to be dark, it wasn't going to be sensational."
The film revolves around Sutcliffe's relationship with a psychiatrist and explores his early years growing up and the bonds he formed as an adult, particular with his wife Sonia.
Blending the film with archive footage, Kite insists he went to great lengths to ensure the story was factually accurate and period details authentic.
"Officers who were involved with the investigation said the only thing that was special about Sutcliffe was that he wasn't special at all.
"There's a temptation with such high profile killers to portray them as vampires or monsters. Sutcliffe was an apparently ordinary bloke and it was that ability to blend into the background that allowed him to evade capture for so long."
In Kite's film, the ordinary man is played by Sheffield actor Walt Kissack, who with a little help from Leeds special effects company Hybrid FX, bears a frightening resemblance to Sutcliffe.
"Sometimes I'd catch a glimpse of him and have to do a double-take," says Kite. "It was important to get the look right, but really this film is about shedding new light on a man who is a closed book.
"There were some psychologists I spoke to who have no doubt that he is a paranoid schizophrenic, but I also know it's an opinion not shared by everyone. I don't know what the truth is, I'm not sure anyone does, but I wanted to put the story in front of an audience and say there you go, you decide.
"Sometimes I think we live in the United States of Amnesia, but a man like this shouldn't be forgotten and neither should his crimes."