John Wayne Gacy, the notorious “Killer Clown,” is set to be the subject of a new Peacock limited series — news announced this week that’s appalled one of his victims’ family members.

Lorie Sisterman, sister of James Haakenson, who was identified as Gacy’s 24th victim in 2017, 40 years after he went missing, tells 360aproko she’s not supportive of the project in any way, shape, or form … and doesn’t understand the need to rehash old wounds and drudge up a hurtful past.

To add insult to injury, she tells us no one reached out to her about the scripted series … which is based on Peacock’s 2021 docuseries “John Wayne Gacy: Devil in Disguise.”

Lorie reiterates the series should be off-limits ’cause there are people alive who are still grieving over Gacy’s actions. You’ll remember … he was executed in ’94 after being convicted of murdering 33 young men and boys during the ’70s, burying most bodies under his Chicago-area home.

Among those grieving are members of Gacy’s family … and Lorie notes the new series isn’t fair to them either — especially for his children, who changed their names to start a new life.

Lorie also addresses the Hollywood treatment given to true crime stories, noting that the Evan Peters-starring Netflix series “Dahmer – Monster: The Jeffrey Dahmer Story” would’ve been equally as horrible for the victims’ families.

She didn’t watch the 2022 show … but she’s worried JWG will be put up on a pedestal like Dahmer.

All in all, Lorie says that even decades later, Chicago’s trying to move on from the evil tragedy … but this new series is a massive setback for them.