The Name of the Son of Sam Game in 'Only Murders in the Building' Has Sinister Origins

Warning: The following article contains spoilers for Season 2, Episode 5 of Only Murders in the Building on Hulu.

Episode 5 of Only Murders in the Building Season 2 introduced fans to the Son of Sam card game. Oliver (Martin Short) explains the rules. Everyone is dealt a card, but only one person gets the Son of Sam card, indicating that they're the murderer of the group.

The lights are then turned off, after which the murderer pinches someone.

After the lights are turned back on, the pinched victim "dies." The surviving players then get a chance to guess who the murderer is and are eliminated if they guess wrong.

But is the Son of Sam card game real, or just something invented for the show? Where did they get the name Son of Sam to begin with? Here's what we know.

The card game Son of Sam isn't real and appears to have been made up for the series. However, the name of the game actually has sinister, real-life origins.

When handing out the Son of Sam cards at Mabel's (Selena Gomez) art-partment party, Oliver references the real-life serial killer upon which the name of the game is based.

Back in July 1976, an unidentified man began terrorizing New Yorkers by shooting and killing innocent people who were simply sitting in their parked cars. (Mostly young, attractive women with long, brown hair.) The random serial killing spree continued until August 1977.

David Richard Berkowitz, who got the nickname of the Son of Sam, confessed to all eight of the shootings that occurred during this time. But why was he known as the Son of Sam killer?

Per a report from History, Berkowitz claimed that his neighbor's dog and demons had ordered him to commit murder. The neighbor's name? Sam. Berkowitz even shot Sam's dog at one point. Thankfully the dog recovered, but Berkowitz's other shooting victims weren't so fortunate.

Per the same report, Berkowitz actually thought Sam himself was a demon, hence the Son of Sam moniker. Unlike most serial killers, whose nicknames are given to them by the public or police, Berkowitz nicknamed himself. He even left a note at one of the crime scenes calling himself the Son of Sam.

One night an eyewitness spotted Berkowitz with a gun on her street moments before shots were fired. The clever witness reminded authorities that they had been writing parking tickets that night.

The police were finally able to arrest Berkowitz after finding his car based on parking tickets issued that evening, and he eventually confessed to everything.

During Only Murders in the Building Episode 5, Oliver attempts to use a round of the Son of Sam card game to get Alice (Cara Delevingne) to confess to Bunny's murder. But Oliver's scheme backfires miserably. Bunny's killer is still on the loose and our crime-solving trio are still stumped.

Will they be able to solve the case and exonerate themselves? We'll just have to wait and see when new episodes of Only Murders in the Building Season 2 drop every Tuesday on Hulu.