A sibling dispute ended with the death of two brothers on Monday morning, bringing the total number of homicides in New Haven to 12 this year.

Daniel Shwisha, 44, fatally shot his brother, Gordon Shwisha, 45, outside of their family business’ facility shortly before 7:50 a.m., and later killed himself at their parents’ home in Westport, police said.

The New Haven Police Department received reports of gunfire in the parking lot of Electrix, Inc., a large architectural lighting fixture wholesaler located at 45 Spring Street, department spokesman David Hartman said. When the officers arrived at the scene, they found the body of Gordon Shwisha, which had suffered from multiple gunshot wounds, in his Jeep Grand Cherokee. Shwisha, the owner of Electrix, Inc. was pronounced dead at the scene.

At approximately 8:30 a.m., Daniel Shwisha drove to his parents’ home at 10 Rustic Lane in Westport, where he shot himself in the head, police said. The parents of the suicide victim — Haim and Birthe Shwisha — called the Westport Police Department to report the incident, saying they were not sure if their son was still breathing. The Westport police and emergency medical units, unaware of Shwisha’s involvement in the recent homicide in New Haven, responded to the scene and began treatment of the victim, according to Westport Police spokesman Sam Arciola.

Arciola said Daniel Shwisha was transported to Norwalk Hospital, where he was pronounced dead at 9:13 a.m.

While Shwisha was being treated, the Westport police received a call from the NHPD reporting that the suspect in yesterday morning’s homicide, who they identified as Daniel Shwisha, might be heading to the Rustic Lane residence, Arciola said.

The New Haven and Westport police departments said they will work closely with each other to investigate any connection between the two incidents.

Repeated calls to the Electrix, Inc. facility went unanswered, but employees interviewed by the New Haven Register yesterday morning said there had been tensions between the two brothers over the family business.

The Secretary of State’s business listings identifies Haim Shwisha as president of Electrix, Inc., Gordon Shwisha as secretary and Daniel Shwisha as director.

According to its website, Electrix, Inc. “is an established architectural lighting fixture manufacturer” and has been in business since 1962.