The 17-year-old son of a former Indian Army officer, the lone survivor of his father's killing spree that wiped out the rest of his family, was battling for life, even as investigators were trying to determine a motive for the shocking murder-suicide.
The teenager, identified as Chris Singh, underwent surgery at a Fresno hospital for head trauma after he was shot by his father on Saturday, local newspaper Fresnobee reported.
Doctors have said his injuries were life-threatening, without giving further details.
Spokeswoman of the community regional medical center, Mary Lisa Russell said that the boy was in critical condition.
Fresno County Sheriff Margaret Mims said Avtar Singh, a former Indian army major who owned a Selma trucking company, apparently shot and killed his wife and two other sons, aged 15 and 5, before killing himself. Mims said Singh called Selma police at 6:15am on Saturday to report that he had killed his family and was going to kill himself.
Authorities have not yet officially released the names of Singh's wife or the two sons who were killed.
The people in the community where Singh and his family lived were shocked with the incidents.
"Our community is completely shocked...It's a misfortune, especially for the children who died," said Rajbir Singh Pannu, president of the town's gurdwara.