Investigators say the suspected gunman quietly prepared for the attack before confronting his brother outside a home.
SANTA CLARA, Calif. — Authorities say a man from Indiana spent weeks preparing for a deadly confrontation with his estranged brother in Santa Clara before carrying out a daytime shooting that ended with a house fire and his own death.
Santa Clara police identified the suspected gunman as Matthew Heflin, 49, of Bloomington, Indiana. His brother, Mark Heflin, 52, was killed outside his home on Enright Avenue on May 8. Investigators believe Matthew Heflin traveled to California in April, remained in the South Bay for several weeks and later rented a short-term home directly next to his brother without the family’s knowledge. Police described the killing as deliberate and targeted but said the motive behind the attack remains unclear.
The shooting happened shortly after noon in a residential neighborhood lined with single-family homes near schools and local parks. Authorities said Mark Heflin had stepped outside to retrieve belongings from his car when his younger brother approached him. Police Chief Cory Morgan said investigators believe Matthew Heflin concealed a handgun inside a paper bag before opening fire following a short exchange between the two men. Neighbors called 911 after hearing rapid gunshots echo through the street. Responding officers arrived within minutes and found Mark Heflin critically wounded near the driveway area. Despite emergency medical efforts, he died before he could be transported to a hospital.
Investigators said the suspected gunman then moved back into the rental property next door while officers attempted to secure the neighborhood. Additional gunfire was heard from inside the home before smoke began rising from the rear of the building. Firefighters entered the area cautiously because police were uncertain whether the suspect remained alive and armed inside. Tactical officers evacuated nearby homes while drones monitored the structure from above. Authorities later discovered Matthew Heflin dead inside the burned residence. Police recovered multiple firearms near the body and said several weapons had been brought from Indiana during the cross-country trip. Detectives also located ammunition, cash and fire-starting materials inside the damaged house.
Police said the brothers had not maintained contact for roughly three years before the killing. Investigators have not publicly discussed the reason for the estrangement, and relatives reportedly told authorities they were unaware Matthew Heflin had traveled west. Officials said he rented a vehicle for the trip and drove more than 2,000 miles before arriving in California. Records reviewed by detectives showed he spent time in the greater San Jose area before securing the rental property beside his brother’s home days before the attack. Authorities have not said whether the location was chosen weeks in advance or shortly before the shooting.
The violence stunned residents in the neighborhood, where many families were home during the midday emergency. Witnesses described hearing repeated gunshots followed by sirens, shouted evacuation orders and heavy smoke drifting above rooftops. Some neighbors said they initially believed construction equipment or fireworks caused the noise before seeing police rush into the area carrying rifles and protective gear. City officials later praised emergency crews for evacuating homes quickly while firefighters battled flames under dangerous conditions. Mayor Lisa Gillmor publicly expressed condolences to the victim’s relatives and called the incident heartbreaking for the entire community.
Authorities continue to investigate the circumstances surrounding the attack, including whether the suspect communicated with anyone before traveling to California. Detectives searched Matthew Heflin’s Indiana residence but said they did not recover any written explanation or threats connected to the case. The Santa Clara County medical examiner ruled that Mark Heflin died from multiple gunshot wounds. Investigators are still awaiting additional forensic results tied to the suspect’s death and the recovered firearms. Police said no future arrests are expected, but the case remains active as investigators review digital evidence and interview family members.
Author note: Last updated May 15, 2026.