Decades later, whether Friday the 13th Part V: A New Beginning should be considered canon is still hotly debated. The Friday the 13th movies are one of the most popular horror franchises of all-time, even if the quality varies as much as your chances of surviving a night at Camp Crystal Lake.
The first Friday the 13th movie debuted in 1980 capitalizing on the slasher genre's rising popularity and spawned a total of twelve films, including a 2009 remake and crossover with Freddy Krueger from A Nightmare on Elm Street. Jason Voorhees, the hockey-mask-wearing killer, serves a the driving force of the franchise, even though the character wasn't even the killer in the first movie. That's not the only time that Jason doesn't get to take control of the kill count in a Friday the 13th movie, however.
Friday the 13th Part V focused on Tommy Jarvis years after he survived Jason's attack in the previous movie. Tommy, still mentally struggling from the horrific event, moved from institution to institution before he ended up at Pinehurst Halfway House. During a confrontation at the halfway house, a boy named Vic killed another boy, Joey Burns. When the murders continue, panic ensued as everyone thought Jason had returned from the dead. In reality, Roy, the father of Joey, was identified as the killer: the grief-stricken father impersonated Jason to avenge his son's death.
Not only is this the only movie where Jason doesn't appear, but there's also conflicting evidence whether Friday the 13th Part V should be considered canon at all.
It makes complete sense why some Friday the 13th fans view A New Beginning as non-canon simply because Jason was not directly involved in the killing spree. But what really holds it back is the ending, where Tommy was shown wearing the infamous mask and teased to become the next major killer. The following installments never followed up with that scene, acting as if it never happened. Another key detail that non-canon debaters point out is that fact that Friday the 13th Part V suggested that Jason's body had been cremated, yet at the start of Friday the 13th Part VI: Jason Lives, he's buried in a local cemetery.
However, there's a lot of ways to make those discrepancies work in Friday the 13th canon. Tommy can dig up Jason's grave in Friday the 13th Part 6 because the killer's cremation was just a rumor. As for Tommy's brief moment in the hockey mask, that can be read as a simple lapse; indeed, the end of Friday the 13th: The Final Chapter (the fourth film released) had a similar tease that went nowhere.
Regardless of canonicity, it's worth noting that Friday the 13th Part V is very much in the thematic spirit of the original movie. Joey's death made Roy go insane, just as Mrs. Vooheers snapped after the death of Jason; he went after everyone at the halfway house just as she killed the negligent camp counselors. Losing a child took both Mrs. Voorhees and Roy Burns' sanity and caused them both to enter rage-driven murder sprees.
There are definitely plot holes in Friday the 13th Part V when taking the franchise as a whole into consideration. But that's pretty common with long-running franchises that jump between writers, especially something as low-budget as Friday the 13th. Ultimately, viewers are able to view the movies however way they please.