So, we have a defendant with zero connection to Steinle. He had a history of drug crimes but no known violent crimes. The bullet that killed Steinle hit the ground and then ricocheted upwards. There was a video possibly showing another group of people disposing of the gun where Garcia Zarate said he found it.
Reviewing the SIG Sauer website shows these handguns cost $1,000 or more. You can see how defense counsel could easily argue that a homeless illegal immigrant would be unfamiliar with one.
All of this adds up to the defense presenting a plausible explanation for how Garcia Zarate could have fired the gun and killed Steinle by accident. That’s reasonable doubt.