Singh killed his wife and two sons and grievously injured his another son, before turning the gun on himself last week in Fresno County in California.
Canadian authorities had let Indian officials know Singh was living in Canada in 2004, according to court documents shown to the Associated Press.
The Singhs lived in Canada with family relatives for two years and applied for asylum, but their claim was denied, according to Singh's US asylum documents provided to AP by his immigration consultant.
After his cover was blown, Singh and his family crossed illegally into the US and settled in Fresno County, where Singh filed an asylum case for himself in 2011.
"He told me, ‘My job in India was to eliminate terrorists who were against the Indian government. I was good at that, they never found the bodies when I did it,'" said Stephens, Singh's immigration consultant.
In his asylum application, Singh said he did not kill Kashmiri activist Jaleel Andrabi, but knew who did. “I am being made a scapegoat," he said, adding that he would be killed if he returned to India.
Singh lived quietly in California initially, working at a truck wash and at a sandwich shop. He eventually started a trucking business, he owned five tractors and trailers, which he named Jay Truck Lines, after his third son, a US citizen.
“He was so nice with everyone, with our community. And he was very good to his wife and children," said Balvir Singh Grewal, who worked as a driver for Singh. “I never saw him angry."
Community members in Fresno said Singh did not hide that he was an Indian army major, but he omitted the salient detail that he was wanted for murder in his homeland. “We don't go anywhere. We don't have outings or a happy life. We are fearful," Singh's wife told a social worker in March in preparing for an asylum claim.
Singh, working as a truck driver in 2007, was detained by immigration agents in Iowa. Immigration and Customs Enforcement had received an anonymous letter stating Singh may have committed fraud to obtain legal status in the United States, said ICE spokeswoman Virginia Kice.
At the time, Kice said, ICE did not know about Singh's murder charges in India. While he was placed in removal proceedings, Singh was released on a USD 4,000 bond. Two years later, India requested that Interpol issue a so-called “red notice" that Singh was wanted in India.
When Singh resurfaced in Selma in the domestic violence case in 2011, Interpol in Washington passed the message of Singh's whereabouts to Interpol in India, said agency spokeswoman LaTonya Miller.
Interpol Washington officials said the US does not consider an Interpol notice alone to be a sufficient basis for the arrest and detention of a person.So Singh bailed out of jail on the felony domestic violence charges.