The Chilean citizen accused of shooting his upstate girlfriend and his two teenage sons — killing one of the boys — is an illegal immigrant who sneaked back into the U.S. after being deported, federal sources told The Post Thursday.

Fernando Andres Jimenez Meza, 40, was deported 20 years ago after being caught at the US border in California, but returned to the country on Monday when he allegedly shot his girlfriend Christina Raimondi and the two her sons in a home on Route 6 in Somers.

dragging triggered a massive manhunt which ended when he was caught in Putnam County.

According to Immigration and Customs Enforcement, Jimenez Meza was arrested in Tecada, California on August 11, 2004 and claimed to be a native of Mexico named Erik Melendez-Arellano.

ICE said he was voluntarily deported to Mexico but re-entered the U.S. at some point.

Jimenez Meza was arrested in Yonkers on Sept. 11, 2018, on a charge of driving under the influence, but was released on a $500 fine, according to records and sources.

ICE said the agency lodged an immigration detainer with the Westchester County Jail on Wednesday.