If you've watched a lot of true crime documentaries, you might ask 'how could no one realise that they were living next door to someone like that?' 

We speak to James (find him on Twitter @ flatearthaddict), who grew up just a few streets away from Dennis Nilsen in North London, and can answer just how murderers can operate in plain sight.

Scotsman Nilsen admitted to murdering at least 15 men before he was apprehended on February 9 1983, and until Dr. Shipman, was the UK's most prolific serial killer. 

He was caught after his neighbours complained of drain problems... and plumbers found a mass of human flesh and bones. 

To get rid of his victims, he had dissected them, boiled them up and flushed their remains down the toilet. 

This audio programme also includes soundbites from Dennis himself explaining his despicable actions, and gruesome quotes from news reports from the time of his arrest.   

Get more true crime content (and other strange, gross, and weird pop culture!) at www.sinisterisles.com

Sinister Isles radio: Growing up in the shadow of Dennis Nilsen

Most people wouldn't want a creepy ventriloquist's dummy's head in their house - and they certainly wouldn't keep it around after videoing it 'coming to life' in the middle of the night! 

In the second episode of Sinister Isles Radio, we meet Michael Diamond, the current custodian of Mr. Fritz, a scary (and 'active') piece of wartime memorabilia that you'll never forget. 

Last October, he released a video that showed the eerie head blinking on its own in the middle of the night. He set up a camera after noticing that Mr. Fritz's eyes were opened or closed, and his glass case was changing position or mysteriously opening, despite the door being a very snug fit. You can see the video on our Instagram, @sinisterisles, and on our website, www.sinisterisles.com

Michael told us: "I treat him with respect...but I am wary of it. There is some sort of residual energy in it. I don't know if what's making him so active is that there is a spirit in visitation."

Until lockdown is lifted, Michael's plans to get some psychic pals over to try to communicate with Mr. Fritz is on ice - but we've asked him to update us when they do.

Some might say Mr. Fritz isn't the creepiest thing in Michael's 'Freak Room'. He's got ceremonial items, execution swords, bits of bone, witches' wands - and ceremonial bowls made from human skulls. 

Find out more about Michael's work by looking up Doctor Diablo's Sideshow on YouTube, or looking for Doctor Diablo on Facebook.