In this July 7, 2015 file photo, Jose Ines Garcia Zarate, right, is led into the courtroom by San Francisco Public Defender Jeff Adachi, left, and Assistant District Attorney Diana Garciaor, center, for his arraignment at the Hall of Justice in San Francisco. San Francisco District Attorney George Gascon, Tuesday, Dec. 5, 2017, defended the handling of the murder trial that ended with the acquittal of Garcia Zarate, whose arrest set off a fierce national debate on immigration. (Photo: Michael Macor/San Francisco Chronicle via AP, Pool, File)

The jury made the right decision, considering the testimony and evidence given to them, argues one alternate juror for the high-profile Kate Steinle murder trial.

Based on the forensic evidence presented at trial, and how it was argued by San Francisco prosecutors, the jury was not able to convict on the homicide charges, writes Phil Van Stockum, who identifies himself as an alternate Steinle juror, in Politico this week.

Jose Ines Garcia Zarate, a Mexican national who illegally immigrated to the U.S. and has previous felony convictions and deportations, was found guilty by the jury of a count of being a felon in possession of a firearm and could face three years in prison. But he was cleared of the murder and manslaughter charges.

Van Stockum said the jury found it could not convict the homeless man on those more serious counts, based on the forensic evidence—and how prosecutors presented it.

“Most of the confusion I’ve encountered has been over this part of the verdict, and it does seem to me personally that manslaughter is the appropriate charge for Steinle’s killing,” he writes. “However, given the evidence and the law presented in this trial, it is clear to me that the jury made the right decision.”

The bullet fired from the stolen .40-caliber Sig Sauer pistol was fired from about knee height, and the bullet struck the concrete 12 feet from where Garcia Zarate was sitting, ricocheting and striking the 33-year-old Steinle in the back about 78 feet away, Van Stockum explains. The immigrant, who had no documented history of violence, contended that he found the gun near the park bench wrapped in clothing or cloth, picked it up, and it accidentally discharged from his inadvertent touch.

In this July 17, 2015 file photo, flowers and a portrait of Kate Steinle remain at a memorial site on Pier 14 in San Francisco. (Photo: Paul Chinn/San Francisco Chronicle via AP, File)

Key pieces of evidence included: the light trigger pull and lack of a safety on the Sig Sauer P239 (stolen from the vehicle of a federal Bureau of Land Management ranger days earlier), and only a “single particle of gunshot residue” found on Garcia Zarate’s hands.

The first witness for the defense was James Norris, a former head of the San Francisco police crime laboratory, who testified about the lack of gunshot particle on Garcia Zarate’s hands—and who also said the accidental firing claim by the accused could explain much of the evidence gathered by police.

The prosecutors had to prove the involuntary manslaughter charge by proving a crime was committed that caused death—and in the Steinle case, they argued it was “brandishing” the weapon, by waving it with menace or threatening intent. But Van Stockum and the other jurors apparently never saw or heard any evidence of Garcia Zara holding the weapon—much less “brandishing,” he writes.

“Given that baffling choice by the prosecution, the manslaughter charge was a nonstarter for the jury,” the alternate juror writes. “Had a different precursor crime been chosen—for instance, the unlawful possession of a firearm by a felon—the outcome might have been different.”

That possession argument could have been made because the accused appeared to indicate during his interrogation by detectives that he had found the weapon 20 minutes prior to the fatal shot—and that he appeared to know that it was a handgun before it discharged. (Garcia Zarate also told investigators he had fired the gun, but he was aiming it at a seal, and not Steinle.)

The Steinle death, and the Garcia Zarate prosecution, has been a political lightning rod over illegal immigration and “sanctuary cities.” U.S. Attorney General Jeff Sessions cited the case earlier this week in a speech to international law enforcement at the Global Forum on Asset Recovery. Sessions said “Steinle would be alive today” if the city of San Francisco had cooperated with immigration enforcement. The following day, federal charges of weapons possession were announced against Garcia Zarate.

On the state weapons conviction, Garcia Zarate faces up to three years behind bars.