The crossover event between New Girl revealed that the two comedies exist within the same universe, but it also created a plot hole involving Jake’s (Andy Samberg) half-sister, Kate Peralta (Nasim Pedrad). The crossover event occurred on both shows, with Brooklyn 99’s crossover episode “The Night Shift” airing first on FOX followed directly by New Girl’s crossover episode “Homecoming,"
In “Homecoming," Jessica Day and her roommates from apartment 4D travel to New York where Schmidt (Max Greenfield) is being honored by his old high school. While Jess is the only New Girl character to appear on Brooklyn 99, after her car is commandeered by NYPD Detective Jake Peralta to pursue a criminal, Jess meets multiple Brooklyn 99 characters from the 99th precinct in the New Girl crossover episode, including Captain Raymond Holt (Andre Braugher) and Gina Linetti (Chelsea Peretti).
While Kate only appears in a single episode of Brooklyn 99, Nasim Pedrad also plays a substantial role on New Girl as Aly Nelson, Winston's (Lamorne Morris) LAPD partner, and a problem arose once the two comedies were connected. Her character isn’t actually featured in either of the crossover episodes, connecting the two series created a plot hole through the former SNL actress' completely separate roles on New Girl and Brooklyn 99.
Within Brooklyn 99, Jake’s father Roger Peralta (Bradley Whitford), an airline pilot who travels frequently for work, is infamous for being both irresponsible and promiscuous, which results in Jake having multiple half-siblings across America whom he was previously unaware existed. One of those siblings, Jake’s half-sister Kate, is introduced in the season 5 episode “DFW,” when she travels from Dallas to New York City to meet her brother for the first time. While Kate and Jake bond over their father’s past blunders, Kate seems to be very similar to their father, since she proves to be a con woman who hooks up with a random street performer on her first day in New York.
The characters played by Nasim in New Girl and Brooklyn 99 are clearly two different people despite looking exactly alike because, not only does Aly live in Los Angelos and Kate live in Dallas, but both characters are complete opposites of each other. Aly Nelson was introduced as a by-the-book police officer in the New Girl season 4 episode “Shark” and was present periodically until the series finale in season 7. Over the course of season 5, Aly is wary of dating Winston despite their connection because she considers it unprofessional to date her partner. In comparison, Kate Peralta is more irresponsible and has no respect for the law, since she gets herself arrested twice in a single episode and runs multiple cons in which she plants glass to receive free plane tickets and meals. Unlike Aly, Kate is also impulsive when it comes to relationships since she’s willing to reunite with her ex-boyfriend Kurt (Kirk Fox) despite the fact that he cheated on her.
While neither Brooklyn 99 nor New Girl provides an explanation for why Aly and Kate essentially appear the same, Nasim Pedrad isn’t the only actor who is featured in both sitcoms, creating a similar plot hole. Apart from Nasim, Damon Wayans, Jr. plays the recurring role of “Coach” on New Girl and Stevie Schillens on Brooklyn 99, Jake’s former NYPD partner. Some of the more minor characters from the two series who also appear identical include Dr. Rossi and Nick Miller’s (Jake Johnson) ex-girlfriend Caroline, both of whom are portrayed by Mary Elizabeth Ellis, and Deputy Commissioner Podolski and Gary, a spokesperson for the 2013 Ford Fusion, both of whom are portrayed by James M. Connor. While the mystery behind the similar appearance of Aly and Kate is unanswered, the identical characters throughout both series remains a fun Easter egg for fans.