A former Indian army officer wanted for a 1996 murder killed his wife and two of their children at their California home before apparently taking his own life.
Avtar Singh called police at around 6.15am local time and told them that he had just killed four people, Sheriff's Deputy Chris Curtice said.
Police asked for assistance from the Fresno County Sheriff's Office because Singh was known to have a military background and was wanted by authorities in India for allegedly killing a human rights lawyer in 1996 in the disputed Kashmir region, Mr Curtice said.
When a sheriff's SWAT team entered the home in Selma they found the bodies of Singh, a woman believed to be his wife and two children, aged three and 15. All four appeared to have died from gunshot wounds. A 17-year-old boy also found in the home was suffering from severe head trauma and was "barely alive", Mr Curtice said. The teenager was taken to a hospital where he underwent surgery.
Singh fled to the United States after he was accused of killing lawyer Jaleel Andrabi in India-controlled Kashmir's main city Srinagar.
Mr Andrabi disappeared in March 1996 at the height of an anti-India uprising and his body was recovered 19 days later in a local river. He had been shot in the head and his eyes were gouged out.
Singh, 47, was arrested in February 2011 when his wife reported that he had choked her, Police Chief Myron Dyck said shortly after that arrest. After Singh was taken into custody, police discovered that he was being sought in India.
Several days later India requested that the United States arrest and extradite Singh. It was not clear on Saturday why Singh had remained free since the request.
Mr Dyck did not immediately return a call seeking comment about the 2011 arrest and Selma police referred questions about yesterday's incident to Fresno County sheriff's officials.
Singh owned and operated Jay Truck Lines, a haulage company in Selma. Alli Adan, a driver for the company, said he spent time with Singh in the past week, including Friday night, during which he acted normally. "He was a nice guy," Mr Adan told the newspaper. "I couldn't believe it because I didn't think he could do something like this."