[8] According to various local news agencies, a public safety alert was sent to nearby phones at around 11:20 a.m.[7] A total of 21 shell casings were recovered at the school.

[15] The two victims were identified by the Dane County Medical Examiner’s Office as 42-year-old teacher Erin West of DeForest and 14-year-old student Rubi Vergara.

[17] Natalie Lynn "Samantha" Rupnow (November 7, 2009 – December 16, 2024),[22] a 15-year-old female student at the school, was identified by a law enforcement official as the perpetrator.

Rupnow lived in the Madison metropolitan area for the entirety of her life, with family ties in both Friesland and Randolph, Wisconsin.

[28] A photo of her wearing a KMFDM T-shirt similar to the shirt that Eric Harris, one of the perpetrators of the 1999 Columbine High School massacre, wore in various amateur videos—spread online.

[29] The Boys and Girls Clubs of Dane County hosted a candlelight vigil the day after the shooting at the state capitol grounds.

[2] Police and the Federal Bureau of Investigation (FBI) spoke to the perpetrator's family and students to attempt to find a motive.

[35] On December 17, Barnes told news reporters that investigators are looking into a "combination of factors," including the possibility that Rupnow had been bullied.

[23] Additionally, police are searching the suspected shooter's social media accounts for hints that could help them establish motive behind the attack.

[39][40] However, as a result of his statements and admissions, a gun violence emergency protective (restraining) order approved by a San Diego County judge was served on Paffendorf.

On January 3, 2025, Paffendorf appeared via video in the San Diego County Superior Court for a restraining order hearing.

He called on Congress to take immediate action to address gun violence, emphasizing the need for stronger protections for children in schools.

[43] Wisconsin senators Tammy Baldwin and Ron Johnson posted separate statements on social media offering their condolences and prayers to all the victims, and said they would continue to monitor the situation and assist law enforcement as needed.

"[45] At the vigil, Madison Metropolitan School District superintendent Joe Gothard said that the tragedy occurred less than two blocks from his childhood home.