SAN FRANCISCO (AP) — A key phase of jury selection began Monday in the trial of a Mexican national accused of killing a woman on a busy San Francisco pier in a case that set off a fierce national debate on immigration.

Jose Ines Garcia Zarate, who had been deported five times, has acknowledged shooting 32-year-old Kate Steinle while she walked with her father on the pier crowded with tourists.

Garcia Zarate has said the shooting was accidental and has pleaded not guilty to second-degree murder.

Earlier this month, lawyers summoned hundreds of potential jurors to court to fill out questionnaires. Among other things, they were asked if they could sit through a lengthy trial or had moral qualms about the case.

Superior Court spokeswoman Megan Filly said 160 jury candidates reported Monday for further questioning.

Media was not granted access to the courtroom due to limited space, Filly said. Court officials say media will be allowed to rotate into the courtroom at an unspecified date.

Before the shooting, Garcia Zarate, 54, had been released from the San Francisco Jail after the district attorney dropped a minor marijuana charge. Zarate was freed despite a request from U.S. Immigration and Customs Enforcement to detain him for further deportation proceedings.

The San Francisco sheriff, citing the city's policy of limited cooperation with federal immigration officials, ignored the ICE request.

President Donald Trump referred to Steinle's death while campaigning as a reason to toughen immigration policies in the country.

Trump has since threatened to withhold federal funding to so-called sanctuary cities such as San Francisco, several of which have filed lawsuits to prevent the move.