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 Kashmir, Curtice said.
When a sheriff's SWAT team entered the home they found the bodies of Singh, a woman believed to be his wife and two children, ages 3 and 15, Curtice said. 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," Curtice said. The teen was taken to a hospital where he underwent surgery. His condition wasn't known.
Singh fled to the United States after he was accused of killing lawyer Jaleel Andrabi in Srinagar.
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 gouged out.
Singh, 47, was arrested by police 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 wasn't clear on Saturday why Singh had remained free since the request.
Dyck didn't immediately return a call seeking comment Saturday about the 2011 arrest, and Selma police referred questions about Saturday's incident to Fresno County sheriff's officials.
Selma police last had contact with Singh about two months ago when he called to complain that reporters wouldn't leave him alone because of the murder warrant, Fresno County Sheriff Margaret Mims told the Fresno Bee.
Singh owned and operated Jay Truck Lines, a trucking company in Selma. Alli Adan, a driver for the company, said he spent time with Singh this past week, including Friday night, and Singh acted normally.
"He was a nice guy," Adan told the newspaper.
"I couldn't believe it because I didn't think he could do something like this."