"Attention amateurs, professionals, criminals, blue collar, white collar. You have wronged people. It is to people you must apologise... Get your misdeeds off your chest! Call Apology."
So read the posters plastered across New York City in 1980.
It was the beginning of a bold social experiment created by local artist Allan Bridge using what was then new technology: the answering machine.
Thousands of people availed themselves of the opportunity to confess their transgressions, anonymously and without repercussions.
In 1983, Allan started playing select calls on the telephone confessional's outgoing message, meaning all who dialled the number could hear and respond to them. It turned the 'apology line' into a sort of rudimentary forum, allowing a dialogue between callers.
Among them were adulterers. Petty thieves. Cheats, cons and gamblers. People who'd wronged friends or family. And murderers.
It was them who intrigued Allan most. At one point, he left a message of his own using the pseudonym Mr Apology. Addressing those "who've done bad things", he asked if they lived their life according to some sort of code, whether they felt they were making a positive contribution.
That's when an apparent serial killer called.
"It was a different kind of fear." Life with Mr Apology.
Lured to the line by Allan's question, the man who called himself Richie answered in a low, slow, monotonous voice. There was no code, he explained. He killed purely for pleasure.
"It's very difficult to describe. It's a real high. My body is alive, every piece of me I know exists at that moment is [alive] when I'm with somebody who's tied up, who's in great pain and who I have complete control over."