IBERVILLE — A second lawsuit against the Iberville Parish Sheriff's Office was filed today in response to the October 2025 shooting that killed a deputy and injured another.

Deputy Charles Riley was killed and Brett Stassi Jr. seriously injured when a suspect that was being interviewed at the courthouse grabbed Stassi's gun and began firing.

The plaintiffs in this lawsuit are Kathryn Gauthreaux, the fiancée of the late Lt. Anthony Mascaro, who responded to the shooting scene, and Deputy Makayla Stewart, a trainee who was there when it happened.

The suit—alleging negligence and wrongful death—says the trauma of the events that day caused both Mascaro and Stewart to develop crippling PTSD, which Mascaro's fiancée alleges led to his fatal heart attack in March.

Deputies planned to interview Latrell Clark, a subject in an ongoing investigation, who had voluntarily arrived at the courthouse for questioning on Oct. 6. According to the lawsuit, the operation progressed from a voluntary interview to an attempted custodial arrest within a secured interview room in the courthouse. Clark, who was being questioned for sex crimes, grabbed Stassi Jr.’s gun and shot him as well as Riley, who died of his injuries. Clark also fatally shot himself. 

Responding to the scene was Mascaro, who arrived at the courthouse around 8 p.m. and attempted life saving measures on Riley, and Deputy Mickyla Stewart. The lawsuit states that during the event, Mascaro and Stewart sustained severe psychological injuries, including PTSD. Mascaro died on March 22.

In the immediate aftermath of the event, Stewart and Mascaro were called into the local sheriff’s office as detectives with the department and Louisiana State Police reviewed footage of the incident, making the officers “relive the tragic incident.” Stewart was questioned until 2 a.m. about the event, the lawsuit alleges.

In her lawsuit, Gauthreaux seeks recovery for Mascaro’s damages, specifically physical pain and suffering, mental anguish and emotional distress, medical treatment expenses incurred prior to death, funeral expenses and all associated costs for the final burial and all other damages Mascaro would have been entitled to assert.

On her son’s behalf, Gautreaux states in the lawsuit that her son has lost his father’s love, affection, companionship, guidance and society. She also asks for damages on her son’s behalf.

Stewart is also seeking damages for pain and suffering, mental anguish and emotional distress, loss of enjoyment of life, among others. 

The plaintiffs blame Stassi Jr. for a series of failures, including not having proper security and having an unsecured weapon in the interrogation room. Stassi Jr. is also accused of inviting his girlfriend and daughter to be present at the courthouse during the operation, which the lawsuit says conflicts with sound law enforcement practice.

Stassi Jr., his father Sheriff Brett Stassi Sr., and the Iberville Parish Sheriff's Office are named as defendants.