In a new motion filed Thursday, Jose Ines Garcia Zarate's lawyers say for a brief moment their client held the gun after it accidentally went off, and then tried to quickly get rid of it by throwing it in the waters of the bay.
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That, they say is "momentary possession," which is not considered unlawful.
"The gun fired, but at that moment he knew it was a gun and as he threw it, he had this very momentary possession that they felt compelled to convict him of, Defense Attorney, Matt Gonzalez told reporters outside the courtroom.
But the jury was never instructed by the judge to consider "Momentary possession," instead convicted Garcia Zarate of possessing a firearm.
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The defense always maintained that Jose Ines Garcia Zarate found the gun that killed Kate Steinle wrapped in a piece of cloth under a chair at Pier 14, and while handling the item, the gun went off.
The prosecution now has until January 2 to oppose the motion.
"Once they file it, we'll evaluate it and we'll go from there," said Alex Bastian, spokesperson for San Francisco District Attorney's office.
Still, this new motion will not affect his sentencing date which is January 5 because Garcia Zarate has served the maximum penalty of three years.
Regardless of the outcome, Garcia Zarate has now been indicted by the federal government on charges of being a felon in possession of a firearm and ammunition and for being an undocumented immigrant in possession of that firearm.
"Once the state proceedings are resolved, the defendant will not be released into the community because there is a pending federal warrant and the federal government will come and pick him up and take him into federal custody, " explained former prosecutor John Creighton.
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