Washington County, WI – A 19-year-old woman from the Town of Addison was initially identified as a suspect in an alleged Mooresville High School shooting plot after a tip was forwarded to the Washington County Sheriff’s Office. However, through a complex multi-agency investigation, authorities determined that the actual suspect was 18-year-old Trinity Shockley from Indiana, who has since been arrested and charged.

The Investigation Unfolds

On the evening of Monday, February 10, 2025, the Washington County Sheriff’s Office Dispatch Center received a critical tip from the Wisconsin Department of Justice regarding threats to carry out a school shooting on Valentine’s Day and to kill the suspect’s best friend.

The tip, which did not identify a specific school, initially named a 19-year-old woman from the Town of Addison as the suspect.

Recognizing the severity of the threat, Washington County Sheriff’s Office personnel acted immediately. The 911 dispatcher alerted a shift supervisor, and authorities placed the suspect’s residence under surveillance while investigators worked throughout the night.

Washington County detectives, in coordination with the District Attorney’s Office, sought to determine the suspect’s possible targets. During their investigation, authorities quickly learned that the Town of Addison woman did not attend any school, and no specific local school was identified as a target.

Role of the Sandy Hook Promise Hotline

The original tip was first received by the Sandy Hook Promise Violence Hotline, which then relayed it to the FBI. The FBI passed the information to the Wisconsin Department of Justice, which ultimately forwarded it to Washington County authorities.

Investigators determined that the suspect was linked to two social media accounts. The FBI confirmed that one of these accounts belonged to the Town of Addison woman, prompting immediate surveillance of her residence.

Authorities obtained a phone number for the tipster from caller ID records at Sandy Hook Promise and maintained real-time communication with the informant. The tipster, who was in direct contact with the actual suspect, provided investigators with critical evidence, including:

• Screenshots of conversations where the suspect discussed plans for a school attack.
• Photos of weapons, ammunition magazines, and a tactical vest.
• Images of the suspect’s bedroom, which displayed numerous photographs of past school shooters.

Narrowing Down the Real Suspect

Early Tuesday morning, the Washington County Sheriff’s Office Multi-Jurisdictional SWAT team executed a search warrant at the Town of Addison woman’s residence, taking her into custody.

During questioning, the woman fully cooperated with law enforcement. It was quickly determined that she was not the individual making the threats but rather had interacted with the actual suspect in an online chat group dedicated to discussing school shooters.

With this new information, Washington County detectives refocused their investigation on identifying the true suspect.

One investigator, using advanced covert online tactics, was able to befriend the suspect on social media. This allowed authorities to obtain crucial user information while simultaneously instructing the informant to obtain the suspect’s phone number.

Upon obtaining the phone number, investigators confirmed that the actual suspect was located in Indiana. The information was immediately forwarded to the FBI’s Indianapolis Field Office for follow-up.

Trinity Shockley’s Arrest in Indiana

By early Thursday morning, the FBI informed Washington County authorities that 18-year-old Trinity Shockley had been arrested in Mooresville, Indiana. Shockley confessed to plotting the murder of her best friend and planning a school shooting on Valentine’s Day.

Authorities have found no evidence linking the Town of Addison woman to the Indiana school shooting plot, and no charges will be filed against her. She was released from custody on Tuesday afternoon.

Averted Tragedy and Law Enforcement’s Response

The investigation remains ongoing, and authorities continue to analyze potential connections and digital evidence. Washington County Sheriff Martin Schulteis emphasized the significance of the anonymous tip and the dedication of law enforcement personnel.

“An absolute catastrophe was thwarted because this tipster—who wishes to remain anonymous—came forward. I have personally expressed my gratitude to them. As I reflect on the gravity of this investigation and the horrific outcomes that could have unfolded had events played out differently, I am truly humbled by the dedication and performance of my staff.”

Authorities stress the importance of public vigilance and the role of anonymous reporting hotlines in preventing acts of mass violence.