Self-proclaimed “predator hunter” Alex Rosen caught Preston Casey Palmer, 34, on Wednesday after he allegedly came to meet a 13-year old and his father for sex.
“He [Palmer] admitted to having a flash drive right there by that paper of 4,000 images and videos of child pornography and it’s on his phone,” Rosen alleged during a video he made of the incident. “He said he’s been grooming kids for about 20 years.”
We just caught Preston Palmer, a long term 3RD GRADE substitute TEACHER at Sullivan STEAM school in Minneapolis.
He brought a flash drive with over 4,000 child p*rn images to go meet a 13-year-old and his dad for sex… pic.twitter.com/shgBBfClT6
— Alex Rosen (@iFightForKids) May 14, 2025
Palmer was arrested by Minneapolis Park Police and is currently being held without bail at Hennepin County Jail on probable cause possession of pornographic work involving minors, jail records show. He has not been formally charged at this time.
Reported Minneapolis Public Schools substitute teacher Preston Casey Palmer, 34, was arrested at Brackett Park yesterday and is being held on PC child porn following a "sting" by self-proclaimed DIY "predator hunter" Alex Rosen.
FYI, in the recent past, local prosecutors have… pic.twitter.com/zWG2KvfCg0
— CrimeWatchMpls (@CrimeWatchMpls) May 15, 2025
According to Rosen, Palmer taught as a substitute at Minneapolis’ Sullivan STEAM School. State records show Palmer holds a substitute teacher license in Minnesota.
Rosen said he caught Palmer off of Bluesky, a left-wing social media platform intended to mimic X. Rosen said he met Palmer at a park down the street from the school where he works.
“Unfortunately there were quite a few kids at the park where we caught Preston, including one of his students,” Rosen said in another video posted to X. “His student talked to us and said he’s always gotten a weird vibe from him.”
“Hennepin County, you’re not going to get away with being soft on crime, not on our f—ing watch,” Rosen added.
Rosen called Palmer a “communist” and said that he “shouldn’t be around kids for a lot of reasons.”
Screenshots of Palmer’s LinkedIn page obtained by Andy Ngo show his pronouns as he/they and that he is a “digital media specialist” and educator. Palmer’s LinkedIn page has since been deleted.
Preston Palmer has tried to pressure @Minneapolis Public Schools @MPS_News to cut ties with police in order to "protect" children. He cited white supremacy as the justification. pic.twitter.com/S79YY2rA7D
— Andy Ngo (@MrAndyNgo) May 14, 2025
Palmer previously pressured Minneapolis Public Schools to cut ties with the Minneapolis Police Department (MPD) in order to protect students after the events of 2020, Ngo reported.
According to Ngo, in a letter asking the district to terminate its contract with MPD, Palmer wrote about his own time at Minneapolis schools, saying, “As a closeted queer student, I worried the officers could be homophobic, because there is a long history of police violence against queer people.” He continued, “As a white student, I saw firsthand how my whiteness was also a shield.”
Minneapolis Public Schools said that it cannot share information about the incident. “The safety of our students is our top priority,” the school said.
“Due to data privacy laws, MPS is unable to share any information at this time. We want to remind our students and community if they see or experience anything concerning to report it to a trusted adult or through our HelpMe App or website,” the district said in a statement.
Hayley Feland
Hayley Feland previously worked as a journalist with The Minnesota Sun, The Wisconsin Daily Star, and The College Fix. She is a Minnesota native with a passion for politics and journalism.
