S.F. pier killing suspect faces additional gun charge

Prosecutors amended their complaint to charge Juan Francisco Lopez-Sanchez (right) with one count of being a felon in possession of a firearm in connection with the shocking July 1 death of 32-year-old Kathryn Steinle. less Prosecutors amended their complaint to charge Juan Francisco Lopez-Sanchez (right) with one count of being a felon in possession of a firearm in connection with the shocking July 1 death of 32-year-old ... more Photo: Michael Macor, The Chronicle Photo: Michael Macor, The Chronicle Image 1 of / 1 Caption Close S.F. pier killing suspect faces additional gun charge 1 / 1 Back to Gallery

The man accused of fatally shooting a stranger who was walking with her father on San Francisco’s Pier 14, in a case that ignited a national firestorm over the suspect’s immigration status, faced an additional gun charge at his third court appearance Tuesday.

Prosecutors amended their complaint to charge Juan Francisco Lopez-Sanchez with one count of being a felon in possession of a firearm in connection with the shocking July 1 death of 32-year-old Kathryn Steinle.

A not-guilty plea was entered on Lopez-Sanchez’s behalf, but once again the defendant — who was freed in San Francisco before the killing even though federal immigration agents wanted to deport him — displayed a lack of comprehension of what was happening in court.

“Not guilty, not guilty,” he said in strained English, after Superior Court Judge Brendan Conroy asked him about his upcoming preliminary hearing.

Lopez-Sanchez, whose age is listed as 45 by police and 52 in jail records, is accused of firing a bullet that pierced Steinle’s heart as she walked along Pier 14 on the busy Embarcadero with her father at about 6:30 p.m.

Police said the gun, a .40-caliber pistol, had been stolen from a federal agent in a car burglary in San Francisco four days prior to the shooting. In a jailhouse interview with KGO-TV, Lopez-Sanchez said the gun went off after he found it wrapped in a T-shirt under a bench — and after he took sleeping pills he found in a trash can.

“There’s nothing in our investigation or review of the material in this case that changes our original opinion of this case — that this appears to be an accidental shooting,” his attorney, Matt Gonzalez, the chief attorney in the public defender’s office, said outside court Tuesday.

The additional charge of being a felon in possession of a firearm refers to Lopez-Sanchez’s long criminal history. He’s been convicted of drug crimes, has spent years behind bars for illegally entering the country, and has been deported five times to Mexico.

Lopez-Sanchez’s immigration status has sparked a national debate. He had been on track for his sixth deportation when he was sent to San Francisco this year on a 20-year-old warrant over an alleged $20 marijuana deal. But when that case was dismissed, the Sheriff’s Department released him, citing San Francisco’s sanctuary city policy.

Lopez-Sanchez is scheduled to return to court Aug. 25 for a preliminary hearing of the evidence.

Vivian Ho is a San Francisco Chronicle staff writer. E-mail: vho@sfchronicle.com Twitter: @VivianHo