Law enforcement officers throughout the East Bay are furiously trying to deal with a shocking rise in gun crimes and a revolving door in the judicial system that releases people arrested in possession of deadly weapons back to the streets.

“This has been building up for some time, but now it has become a real problem,” Oakland Interim Police Chief Susan Manheimer said.

“We’ve recovered over 1,100 guns so far this year, a 38% increase over last year,” she added. “Homicides are up 86% since the COVID shutdown in March and ShotSpotter reports are up 80%. All major cities are seeing this,” she said of the crime landscape across the country.

“It’s off the hook,” Hayward Police Chief Toney Chaplin said.

Hayward has had 10 homicides so far this year, twice the number in 2019.

“And we are seizing guns at the rate of 21 a month since the COVID shutdown began,” Chaplin added.

Manheimer said she, Oakland Mayor Libby Schaaf, the District Attorney’s Office, the Alameda County Probation Department and some judges have been meeting to try come up with a way to hold violent and gun-related offenders more accountable.

“We had a four-hour meeting with one of the judges the other day, where we showed them how we tracked back 15 violent offenders who were released and then committed another violent crime,” Manheimer said.

“One of the cases we brought forward was an individual arrested twice in July and then again in August, and got out on zero bail for the automatic gun possession,” she said. “We knew he was such a risk we started following him and viewed him commit two shootings. He is now in custody.”

Zero cash bail was an emergency policy the state Judicial Council put into effect in April that eliminated cash bail on a number of low-level crimes. The goal was to reduce jail populations to help curb the spread of COVID-19.

The zero-bail order was repealed in June, but Alameda County is among many continuing the practice.

“The key issue is that gun crime is spiking on the streets of Oakland, and when we arrest individuals with assault weapons, that can actually fall under the zero-cash-bail program in Alameda County, and they’re being let back out,” Manheimer said.

“Even in cases where the bail is $500,000, under the current system you can pay that down through a bail bondsman ... and you can be back out on the streets for less than 10% of bail for very significant crimes,” she said. “We want to have those arrested with fully automatic assault rifles held accountable and in custody.”

Alameda County District Attorney Nancy O’Malley appears to be on board as well.

“The D.A.’s office has been part of the working group since its start, and we have led efforts to exempt illegal possession of firearms, especially possession of assault weapons, from the zero-bail formula. This change is clearly crucial to public safety,” O’Malley said.

Meanwhile, gun use has become increasingly common in crimes.

One of the most talked-about examples of the challenge police face is the swarm of armed people who attempted to break into a marijuana operation in a residential section of 92nd Avenue in East Oakland on election night.

The ensuing melee left one suspect dead and three Oakland police officers injured. Nine firearms were recovered at the scene.

Twenty people were arrested on charges ranging from minor, such as obstructing law enforcement, to more serious, like carrying a concealed weapon and assault with a deadly weapon.

According to information correlated by the Northern California Regional Intelligence Center, a federal, state and local public safety program that assists law enforcement agencies, all 20 of the men and women arrested were free within 48 hours.

“So everybody is pretty much out and back on the streets,” Alameda County Sheriff’s spokesman Ray Kelly said.

The 92nd Avenue incident was just one in a string of armed election-night swarmings during which 20 to 50 carloads of people hit big-box stores, pharmacies and marijuana dispensaries from San Lorenzo to Richmond.

And while most of the arrests on the night of the caravans were for nonviolent offenses, police say that when 50 to 100 people swarm into a parking lot, things can turn deadly, so they can’t just charge in to break things up.

“A lot of these individuals are armed and hopped up, so you can wind up creating an even more dangerous situation,” Kelly said.

San Francisco Chronicle columnist Phil Matier appears Sundays and Wednesdays. Matier can be seen on the KGO-TV morning and evening news and can also be heard on KCBS radio Monday through Friday at 7:50 a.m. and 5:50 p.m. Got a tip? Call 415-777-8815, or email pmatier@sfchronicle.com. Twitter: @philmatier