San Francisco District Attorney George Gascon gestures during a media conference on Tuesday, Dec. 5, 2017, in San Francisco. Gascon is defending the handling of a murder trial that ended with the acquittal of a Mexican man whose arrest set off a fierce national debate on immigration. Gascon said Tuesday that he still believes Jose Ines Garcia Zarate should have been convicted of murder in the 2015 death of Kate Steinle. (AP Photo/Ben Margot)

SAN FRANCISCO - U.S. authorities on Tuesday charged a Mexican man with new immigration and gun violations less than a week after a San Francisco jury acquitted him of murder for the shooting death of Kate Steinle, a case that helped fuel a fierce national debate on immigration.

A federal grand jury in San Francisco indicted Jose Ines Garcia Zarate Tuesday on one count each of felon in possession of a firearm and of "being an alien illegally and unlawfully in the United States" in possession of a gun and ammunition, according to the indictment.

A San Francisco jury last week convicted him of a state charge of felon in possession of a firearm after acquitting him of murder and assault for the July 1, 2015 shooting.

The state conviction carries a maximum sentence of three years in jail. He has been in jail since the day of the shooting. His public defender Matt Gonzalez said Garcia Zarate will ask a judge to toss out the state conviction. Garcia Zarate is to be sentenced in state court Dec. 14.

San Francisco District Attorney George Gascon on Tuesday defended his office's handling of the case. He said he still believed Garcia Zarate should have been convicted of Steinle's murder.

Legal experts have said prosecutors overreached by asking for a first-degree murder conviction because the fatal shot ricocheted off the ground, supporting Garcia Zarate's defence that the shooting was an accident. Jurors could also have convicted Garcia Zarate of second-degree murder or involuntary manslaughter but chose not to.

Jurors left court last week without speaking publicly about their verdict and Gascon said they have not spoken with prosecutors either.

Garcia Zarate said he found a gun under a chair on a San Francisco pier. He said it fired accidentally when he picked it up.

President Donald Trump frequently brought up the case last year during his presidential campaign to criticize efforts in the U.S. to combat illegal immigration.

Garcia Zarate had been deported five time before the shooting. The San Francisco sheriff's department also released him from jail several weeks before the shooting despite a request from federal immigration officials to detain him for deporation.

San Francisco is a so-called sanctuary city and local officials are limited in the co-operation they can give with federal deportation efforts.

President Trump has threatened to withhold federal funding from cities with similar policies.

Gascon on Tuesday called Trump a "madman" for a series of tweets deriding the jury's verdict.

News from © The Associated Press, 2017