EXCLUSIVE: CNN spin-off network HLN is developing a follow up to Joke ProductionsGolden State Killer documentary series Unmasking A Killer after police arrested and charged 72-year-old Joseph James DeAngelo for a number of the murders.

Joke Fincioen, who runs the eponymous production company, tells Deadline that it was a “privilege to witness this moment in history” after spending years on the high-end doc project.

Sacramento County District Attorney Anne Marie Schubert announced the arrest last week, coming after Paul Holes, a retired investigator with the Contra Costa District Attorney’s Office and long-time investigator on the case, is thought to have made a break on the case by searching a free genealogy website.

Fincioen says it is now working on a follow-up for the Time Warner-backed broadcaster. “There is a lot to cover and still uncover in terms of the offender and his life. Working with HLN, a news network, has been exciting and invigorating; news moves much faster than documentary producing so it’s a great outlet for the breaking news segments of our story that we otherwise might lose.  We’re able to be part of the conversation, help our documentary subjects navigate this news cycle and support our network in getting the story and getting it right.”

After she heard of the arrest, Fincioen says, “My first thought was ‘Are they sure?’ We know of so many close calls over the years when investigators thought they had their man but then DNA cleared that suspect.  When we were told there was a 100% DNA match, we just started thinking of all the individuals we’ve come to know through this.  The investigators, the survivors, the family members of the victims, their journey has been a lot longer than ours and it’s been a privilege to witness this moment in history with them.”

Supervising producer Todd Lindsey, a true crime expert who spent ten years tracking the case, said he felt a “great sense of relief for the victims, their families, and all of the detectives and investigators who have worked so tirelessly over the last four decades to bring him to justice. It’s such a satisfying feeling to finally put a name, and a face, to this monster and I’m proud to have a played a part in educating the public about this case.”

However, Fincioen says that the focus on the case, including Unmasking A Killer and Michelle McNamara’s I’ll Be Gone in the Dark: One Woman’s Obsessive Search for the Golden State Killer, which is being turned into a series for HBO, helped the case. But she admits that tips generated by the show and book didn’t directly lead to the arrest.

“That said, we’ve received numerous calls and emails from law enforcement thanking us for our series and for accurately getting the story out there.  When we started filming two years ago at the press conference, this task force was taking shape and we’d like to think, that our continued interest, involvement and communication with the different jurisdictions throughout these two years helped to energize the investigation.  In a way, we’ve been cheerleading from the sidelines, keeping the public engaged but the investigators and their tireless work carried this football into the end zone,” she adds.

In addition to the linear series, Joke Productions produced a podcast to run alongside the show with a new episode airing today following the news of the arrest.

“We are prepping the second season of podcast episodes deep diving in the defendant’s history and capture,” adds Joke Productions Co-Founder Biagio Messina.

Joke Productions, which also produces Oxygen’s Three Days To Live, telling harrowing stories of law enforcement working to save abducted women, and feature doc Dying To Do Letterman, is now in the process of pitching two further “high-profile” projects. Messina says, “We have been active in true crime storytelling for a few years now.  It’s a space we’re passionate about and have developed great relationships in.  We’ve been able to build trust with law enforcement and victims’ families, something that is crucial in this space.”

Earlier this week, Deadline revealed that Unmasking A Killer went global with Sky becoming the first high-profile international broadcaster to pick up the Kew Media-distributed doc series.

Jonathan Ford, Executive Vice President of Sales, Distribution at Kew Media Group, tells Deadline that the bidding in the UK was “very competitive” and Sky was “quick to take the show off the market. “We’re experiencing similar levels of interest in other key territories have several other deals at contract stage. We’ve certainly seen a surge in enquiries [since the arrest], the timing has been quite astonishing since the hunt for the killer has been in progress for 44 years,” he adds.

The distributor is now hoping that other true crime titles on its slate can be similarly successful. Other shows on its slate include CNN’s six-part series The Radical Story of Patty Hearst, 52-part Frantic Films-produced In Plain Sight and Laura Paglin-directed feature doc Unseen: Victims & Survivors of the Cleveland Strangler.