This episode is based on the 2014 Isla Vista killings. Holden March is based on the perpetrator Elliot Rodger, who sent an email titled "My Twisted World" to acquaintances and family before going on the shooting. The document quickly became known as his "manifesto". Rodger's had issues feeling he had been rejected by women, despite hardly interacting with them. He also uploaded a video to YouTube (later taken down) before the incident called "Elliot Rodger's Retribution", where he talked of the upcoming attack, and his motives behind it: his desire for revenge against women and sexually active men he perceived to be living a better life than his.
This is the only episode in Season 16 in which Peter Scanavino does not appear since joining the series as Detective Carisi.
Holden is named after the main character in The Catcher in the Rye, the book that inspired Mark David Chapman to murder John Lennon.
First appearance of Peter Gallagher as Deputy Chief William Dodds. Dodds appears in nineteen episodes through season 21.
Benson asks how many of these unknown attack patterns have they investigated this year, to which Rollins replies they are up to "lucky 13". Later in the year, they investigate Pattern Seventeen (2014).