A tragic family confrontation has ended with the death of two brothers. Santa Clara police are still putting together the pieces, but the initial investigation has revealed that on May 8, 49-year-old Matthew Helfin of Bloomington, Ind., shot and killed his brother, 52-year-old Mark Helfin, before setting fire to a home on Enright Avenue. Matthew Helfin died a few hours later.

During a news conference on May 14, Santa Clara Police Chief Cory Morgan said this was an isolated incident. He revealed the results of the initial investigation. According to investigators, Matthew Helfin traveled from his home in Indiana in a rental car, carrying “multiple firearms and ammunition.” Matthew reportedly told a friend he was planning to visit Colorado, but instead arrived in the San Jose area around April 14.

Approximately three days before the attack, Matthew rented the home next door to Mark. Mark and his family were not aware that Matthew was there. In fact, detectives say the two brothers had been estranged for at least three years.

Matthew reportedly had manufactured fire logs delivered to the rental property for his arrival.

Just after noon on May 8, witnesses say Mark was retrieving items from his vehicle when Matthew approached him. After a brief verbal exchange, Matthew, who was concealing a firearm in a paper bag, opened fire. Officers found 12 spent shell casings in front of Mark’s home.

Matthew then retreated through a side yard of the rental property and shot at Mark’s vehicle and house. He returned to the inside of the rental property and set fire to a rear bedroom.

When emergency crews arrived on scene, officers pulled Mark from outside of his home and began life-saving efforts. Mark died at the scene.

At the same time, heavy smoke began to billow. While firefighters tried to put out the fire, there was more gunfire. Officers used armored rescue vehicles, drones and tactical personnel to evacuate residents and protect the firefighters.

Later that evening, the special response team entered the rental property and found Matthew’s body in the rear bedroom. So far, it has not been determined if he died from the fire or from something else.

Chief Morgan said inside the home, investigators found the suspect’s passport, ammunition, manufactured fire logs, about $95,000 in cash and four pistols. So far, investigators have not determined a motive for the attack.

Investigators say Matthew did not have a criminal history in California and his only criminal record in Indiana was a DUI in 2011.

Mark’s family was not home at the time of the shooting. The two men’s parents live in Bloomington, Ind.

Chief Morgan thanked the Santa Clara Fire Department, Sunnyvale Department of Public Safety, Milpitas Police Department, Contra Costa County Sheriff’s Office, Santa Clara County Medical Examiner’s Office, Santa Clara County Crime Laboratory, Santa Clara County Arson Task Force, the Bureau of Alcohol, Tobacco, Firearms and Explosive and the law enforcement in Bloomington, Ind. for their assistance in the investigation.

“I also want to acknowledge the residents of the Enright neighborhood who experienced an extraordinarily frightening and disruptive event,” said Morgan. “Many residents were evacuated from their homes or sheltered in place for several hours while dispatchers, officers, firefighters, investigators and our regional public safety partners worked under rapidly evolving and dangerous conditions to secure the scene and protect the community.”