Donald Trump has condemned a jury’s verdict that a Mexican man is not guilty of murdering a woman on a San Francisco pier.

Jose Ines Garcia Zarate had been deported five times and was wanted for a sixth deportation when Kate Steinle, 32, was fatally shot in the back in July 2015.

He did not deny shooting Ms Steinle but said it was an accident.

The case sparked a national debate on immigration, leading to Mr Trump decrying America's borders in the aftermath of her death. He has also used the case to reiterate his call for a wall on the border with Mexico.

After Garcia Zarate was acquitted of murder by a jury, Mr Trump posted three messages describing the verdict as "disgraceful".

"No wonder the people of our country are so angry with illegal immigration," he said.

"The jury was not told the killer of Kate was a seven-time felon.

"The Kate Steinle killer came back and back over the weakly protected Obama border, always committing crimes and being violent, and yet this info was not used in court.

"His exoneration is a complete travesty of justice. BUILD THE WALL!"

Before the shooting, the San Francisco sheriff’s department had released Garcia Zarate from jail despite a federal immigration request to detain him for deportation.

The decision was made in line with San Francisco’s “sanctuary city” law, which limits cooperation with US immigration authorities.

Ms Steinle was killed while posing for pictures with her father on a San Francisco pier.

The jury of six men and six women — including three immigrants — found Garcia Zarate not guilty of homicide.

Despite being acquitted of murder, Garcia Zarate, 54, was found guilty of being a felon in possession of a firearm.

An hour after the verdict, US Attorney General Jeff Sessions released a statement, saying that sanctuary cities are causing harm to the American people.

“When jurisdictions choose to return criminal aliens to the streets rather than turning them over to federal immigration authorities, they put the public’s safety at risk,” Mr Sessions said.

“San Francisco’s decision to protect criminal aliens led to the preventable and heartbreaking death of Kate Steinle.

"I urge the leaders of the nation’s communities to reflect on the outcome of this case and consider carefully the harm they are doing to their citizens by refusing to cooperate with federal law enforcement officers.”

Garcia Zarate is now expected to be deported.

Acting US Immigration and Customs Enforcement Director Thomas D. Homan said his agency “will work to take custody of Mr. Garcia Zarate and ultimately remove him from the country.”

He also said “San Francisco’s policy of refusing to honor ICE detainers is a blatant threat to public safety and undermines the rule of law. This tragedy could have been prevented.”

Ms Steinle’s father, Jim Steinle, told the San Francisco Chronicle that the family was saddened and shocked by the verdict.

He said: "Justice was rendered but not served.”

Garcia Zarate’s lawyer, Matt Gonzalez, had argued that the defendant was not criminally responsible because he found the .40-caliber Sig Sauer and was not aware it was a gun when it accidentally went off.

San Francisco Deputy District Attorney Diana Garcia said during the trial that she did not know why Garcia Zarate fired the weapon, but he created a risk of death by bringing the firearm to the pier and twirling around on a chair for at least 20 minutes before he fired.

“He did kill someone. He took the life of a young, vibrant, beautiful, cherished woman by the name of Kate Steinle,” she said.

Mr Gonzalez said in his closing argument that it was difficult to believe Garcia Zarate found an object that turned out to be a weapon, which fired when he picked it up.

But he told jurors that Garcia Zarate had no motivation to kill Ms Steinle and that as awful as her death was, “nothing you do is going to fix that.”

The bullet ricocheted on the pier’s concrete walkway before it struck Steinle.

The gun was stolen from the SUV of a US Bureau of Land Management ranger that was parked in San Francisco. The city has been plagued by an epidemic of car burglaries in recent years.

Before the shooting, Garcia Zarate had finished a federal prison sentence for illegal re-entry into the United States and had been transferred to San Francisco’s jail in March 2015 to face a 20-year-old charge for selling marijuana.

The sheriff’s department released him a few days later after prosecutors dropped the marijuana charge, despite a request from federal immigration officials to detain him for deportation.

At the time, former sheriff Ross Mirkarimi defended releasing him, who was held two weeks longer than required by the department’s rules, but ICE had not placed a warrant or court order against him.

*This article originally appeared in USA Today.