A Lot of Guns on the Table: SFPD Makes Big Bust in 'Letterman' Case

San Francisco Police Department sergeants Martin Bandvik and Tigran Antonian thought they'd find a handgun at the end of a two-month robbery investigation that led them to a house on the 100 block of Nursery Way in South San Francisco.

But on June 3, when the sergeants served a search warrant on the house with the San Mateo North County Regional SWAT Team, they found a whole lot more: 22 assault weapons, 12 handguns, two bolt action rifles, two shotguns, hand grenades, bomb making materials, and some 5,000 rounds of ammunition.

"We had no idea it was going to be a cache this big," Bandvik said. "It makes me feel very good. We’re on the street every day in the Bayview, and our brothers and sisters in the Bayview Police Station that are out there -- these are guns that they’re not going to have to deal with now on the street."

Bandvik and Antonian started tracking the case on April 22, after the first in a series of four robberies in San Francisco's Bayview, Ingleside and Marina districts.

"One guy came in with a letterman jacket on and did the robbery," Bandvik said of the incident at a Bayview gas station. "The second guy was in the getaway car. We were able to get some information on that through surveillance video."

Two days later, the letterman jacket showed up again, this time at a Walgreens robbery in the Marina. Two more robberies followed back in San Francisco's southeastern neighborhoods, on May 17 and 19.

On May 24, "some very vigilant, sharp-eyed" Bayview patrol officers spotted 56-year-old Homer Mathews and his letterman jacket on Third Street, Bandvik said, and they arrested him.

Then a Northern Station officer contacted Bayview investigators with information tying the getaway vehicle description to a second suspect, 31-year-old Austen Chin.

"That’s when we served the search warrant in South San Francisco," Bandvik said. "He was arrested and the weapons were found."

SFPD Lt. Bill Braconi said the guns appeared destined for sale in the Bayview.

"Some of the information that we uncovered in the residence indicates that many of these weapons were offered for sale," he said, "and based on information I can’t divulge at this time, it indicates that some of the recipients of these weapons may have been from the Bayview District."

He also said MK105 rounds, military-grade ammunition, was recovered in the search.

"They’re about a 10-inch long shell that’s used in a small cannon," he said.

Braconi said police don't yet know the intentions surrounding the military weapons or explosives, but he said there's nothing to indicate a connection to a terrorist plot.

Crime statistics from SF OpenData show 169 weapons-related arrests in the Bayview District since this time last year. San Francisco Police Chief Greg Suhr said the department's focus on seizing weapons has had an impact on violent crime.

"We think that that’s a large part of the reason why -- although any homicide is one too many -- homicides are basically half of what they were in the mid-2000s," he said. "Gun violence is also down about 50 percent now from what it was in say 2007, 2008. Certainly getting this kind of firepower off the street -- the potential for this kind of weaponry, I can’t imagine."

Braconi said assault weapons are often part of "gun fights that very frequently, all too often ensue in the Bayview."

"These are the types of guns that Bayview officers seize off the street every day," he said. "Where do these guns come from? I think this may be a potential source."

Police said at least one robbery suspect is still on the loose, and their investigation continues.

Both Mathews and Chin were booked in San Francisco County Jail on felony robbery charges. Mathews was booked on robbery and conspiracy to commit robbery; Chin was booked on robbery and kidnapping for the purpose of robbery. The more serious charges stemmed from the fourth robbery, which appeared to involve an unidentified suspect and Chin, but not Mathews, Bandvik said. He said suspects approached grocery store owners in Ingleside outside their store and forced them inside for the robbery.

Police are coordinating with the San Mateo County district attorney and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives on the weapons charges. It has not yet been determined whether Chin and Mathews will be charged federally, Braconi said.

Sgt. Tigran Antonian, who worked the case with Bandvik under Braconi's supervision, said he was shocked to find the weapons stash.

"It was a good case, good bust," he said. "We’re happy to have all these guns off the street."