Former Minneapolis substitute teacher pleads guilty to possession of child porn after sting

MINNEAPOLIS (FOX 9) - A former substitute teacher pleaded guilty to possession of child pornography and soliciting someone who he believed to be a child for sexual conduct. 

Preston Casey Palmer, 35, of Minneapolis, pleaded guilty after being charged with 14 criminal counts related to possession of child porn and attempting to solicit a minor for sex.

His sentencing date is set for the morning of Dec. 3, 2025.

READ MORE: Minneapolis substitute teacher arrested in child predator sting

Minneapolis substitute teacher pleads guilty to child porn, solicitation 

The backstory:

Palmer was arrested earlier this year after Minneapolis Park Police responded to Brackett Park on May 14, 2025, after getting a report that a man at the park was going to disseminate child sex abuse material, according to a criminal complaint filed in Hennepin County Court.

The complaint notes that Palmer is a teacher at a nearby elementary school. 

Arriving officers said they spoke with several people who were part of "an online group aimed at uncovering online activity involving solicitation of minor for sexual acts and dissemination of child sexual material," according to the complaint. 

Those people reportedly told officers that Palmer was speaking to someone he thought was a 13-year-old boy since March 2025. Those conversations were sexually charged and made several references to child pornography. 

The online sting group also led Palmer to believe the 13-year-old boy's father was engaging in similar acts and got him to admit that his "age of attraction is around 8 and up," according to messages cited in the criminal complaint.  

Palmer reportedly thought he was going to meet the father and the 13-year-old boy when he arrived at the park in order to share the child abuse content. The online group then called police when they saw Palmer at the park. 

The complaint states that during the arrest, Palmer made "spontaneous statements" that he was sorry, he was an addict and he will have a felony and be on the registry. 

Authorities are still reviewing the contents of the flash drive and the cell phone that was on Palmer at the time of the arrest. The complaint states a preliminary review of the content showed images of juveniles, some believed to be as young as five years old, performing sexual acts. 

Child predator sting

What they're saying:

The complaint states that during the arrest, a child at the park said, "That's my teacher" when Palmer was taken into custody. 

Minneapolis Public Schools shared the following statement on the arrest:

"The safety of our students is our top priority. 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."

Footage from the group that set up the sting can be viewed below: