Carondelet Sex Offender's Own Registry Check-In Led Police to Child Porn Charges

A 47-year-old Carondelet man already listed on Missouri's sex offender registry is now facing three felony child pornography charges after investigators say the very phone number and email address he was required to report to police helped crack the case wide open. Sean C. Lammers was arrested after reporting to St. Louis police headquarters on June 2, and he remains jailed without bond ahead of a confined docket hearing scheduled for Monday.

According to FOX 2, the case traces back to a tip the National Center for Missing & Exploited Children sent investigators on May 9, alleging that two email addresses had uploaded a video depicting a minor performing oral sex. Those two email addresses were linked to a Google account operated by Lammers, per the St. Louis Metropolitan Police Department. The break came from an administrative detail: back on April 22, Lammers had met with an SLMPD sex offender registry detective to document his phone number and email address, and that information matched what NCMEC had provided in its tip.

A Routine Check-In Becomes Evidence

That April meeting wasn't optional. Under Missouri Revised Statutes § 589.414, registered sex offenders must report any new or altered phone numbers, email addresses, and online identifiers to law enforcement within three business days of acquiring them. Because St. Louis City runs its own sex offender registry through the SLMPD rather than through a county sheriff's office, the detective who logged Lammers's contact information sat inside the same department that would later receive NCMEC's tip.

NCMEC itself functions as a national clearinghouse for these leads. The organization received roughly 36.2 million reports through its CyberTipline in 2023, according to the U.S. Department of Justice, screening account data and IP logs from tech platforms before referring actionable cases to local police. In Lammers's case, NCMEC linked his phone number, email address, and IP address to 42 other tipline reports involving child pornography, investigators say.

Search Turns Up Devices and Videos

Armed with that match, police obtained a search warrant for Lammers's phone and other electronic devices at his Carondelet home, according to police. Officers confiscated eight electronic devices for forensic examination. Investigators say they found three videos containing child pornography on Lammers's phone, forming the basis for the three counts the St. Louis Circuit Attorney's Office ultimately filed against him.

The felony classification of those counts is significant. Under Missouri Revised Statutes § 573.037, possessing child sexual abuse material involving a video or moving image is treated as a Class B felony, a far more serious classification than the Class D felony reserved for possessing a single still image. Missouri law also allows prosecutors to file a separate count for each individual item of illicit material recovered, which is reflected in the three counts against Lammers.

What Comes Next in Court

Lammers has a preliminary hearing scheduled for September 25, in addition to Monday's confined docket hearing. Effective this Friday, Missouri statutes will formally replace the term “child pornography” in Chapter 573 with “child sexual abuse material,” reflecting a legislative push to describe the material as evidence of abuse rather than pornography, though the charges against Lammers were filed under the prior terminology.

Cases like this one sometimes draw federal attention as well. Online child sexual abuse material investigations in the St. Louis region frequently trigger federal jurisdiction under interstate commerce statutes when internet accounts or cloud services are involved, and federal and local child exploitation investigations in the region are often coordinated through Project Safe Childhood, a Department of Justice initiative dating to 2006 that connects local departments with federal prosecutors. It is not yet known whether Lammers's case will draw parallel federal scrutiny.

The case adds to a string of recent child exploitation prosecutions across the St. Louis area. Hoodline has previously reported on a digital trail leading to a Fenton bust, as well as a Wentzville firefighter sentenced to 22 years and a separate St. Louis County case involving a suspect who confessed to soliciting child nudes. Just last year, the St. Louis Circuit Attorney's Office secured a life sentence without parole for a registered sex offender in the Carondelet neighborhood — the same South St. Louis community where Lammers lives — underscoring the office's continued focus on repeat offenders in the area.