A jury on Thursday found Jose Ines Garcia Zarate not guilty of homicide charges in the July 2015 death of Kate Steinle in San Francisco.
Jurors convicted the undocumented immigrant of being a felon in possession of a firearm after deliberating for more than 24 hours over six days.
The case became a political lightning rod in the debate over immigration policy. Proceedings lasted about one month.
Garcia Zarate, a Mexican citizen, is subject to immediate deportation.
He had been deported from the United States five times prior to Steinle's death.
Garcia Zarate, 45, faced a charge of second-degree murder, but jurors also were allowed to consider first-degree murder and involuntary manslaughter convictions.
Garcia Zarate was accused of fatally shooting Steinle, 32, with a Sig Sauer .40-caliber handgun as she and her father walked on San Francisco's Pier 14.
Steinle, her father and a friend were at the San Francisco pier when a bullet struck Steinle's lower back and tore through her abdominal aorta, authorities said.
Surveillance video showed Garcia Zarate running away. After his arrest, investigators found gunshot residue on his right hand, prosecutor Diana Garcia told jurors.
Prosecutors said Garcia Zarate was playing his own "secret version of Russian roulette" and deliberately fired into an unsuspecting crowd on the pier, killing Steinle.
Defense attorney Matt Gonzalez said Garcia Zarate found the gun at the pier. He said it was wrapped in cloth, and when Garcia Zarate unwrapped it, the gun accidentally discharged.
But in a police interrogation, Garcia Zarate admitted to firing the gun, saying he was aiming at a seal.
He told police that he stepped on the gun, causing it to fire.
Prosecutors said Garcia Zarate immediately tried to cover his tracks by throwing the gun into the San Francisco Bay, then fleeing the scene.
Garcia Zarate was formerly known as Juan Francisco Lopez-Sanchez, one of several aliases he is known to have used. CNN and other media outlets previously identified him as Juan Francisco Lopez-Sanchez.
Sanctuary cities and 'Kate's Law'
Garcia Zarate's undocumented status and San Francisco's status as a "sanctuary city" prompted widespread debate over immigration policies.
Garcia Zarate had been deported from the United States back to Mexico five times. Before the shooting, officials in San Francisco released him from custody instead of turning him over to immigration authorities.
Steinle's death became a rallying cry for President Donald Trump and others, who have invoked the case in decrying sanctuary cities and promoting the construction of a border wall between the US and Mexico.
"This senseless and totally preventable act of violence committed by an illegal immigrant is yet another example of why we must secure our border immediately," Trump said in July 2015. "This is an absolutely disgraceful situation and I am the only one that can fix it. Nobody else has the guts to even talk about it. That won't happen if I become President."
Trump also mentioned Steinle in his acceptance speech at the Republican National Convention after winning the Republican presidential nomination.
In June, the House of Representatives passed "Kate's Law," a bill that would create harsher penalties for repeat illegal entry to the US. The bill would also expand US law to pressure local cities to cooperate with federal immigration enforcement.
This summer, the House of Representatives passed H.R. 3004, dubbed "Kate's Law" -- a measure named for Steinle. The legislation would increase maximum prison penalties for immigrants caught repeatedly entering the US illegally.
The measure was introduced in the Senate but failed to get the 60 votes needed to pass.