In the year since Alameda County District Attorney Nancy O’Malley filed criminal charges against six East Bay law enforcement officers for what she called their “morally reprehensible” actions in Oakland’s sexual misconduct scandal, the most severe punishment handed down has been a $390 fine and three years of court probation.

Half of the cases have been dismissed or their charges dropped due to insufficient evidence. Two cases were plea bargained, and one awaits trial.

Critics who wanted to see greater consequences wonder whether the district attorney’s office mishandled the scandal. Some say the prosecution was frivolous.

“When you have decisions like this, it signals, for us, that lack of prioritization — that the safety of vulnerable youth is less important than the image of officers,” said Maheen Kaleem, a staff attorney at the antisex trafficking organization Rights4Girls who previously worked with sexually abused and commercially exploited youth in Oakland. “Victims and survivors won’t come forward. This case signals you won’t be believed.”

Others, like defense attorney and former Alameda County prosecutor Michael Cardoza, say O’Malley’s decision to pursue charges was prompted by political pressure, and the collapse of half the cases was inevitable.

Cardoza said the professional careers and personal lives of the officers involved have been ruined because of the publicity surrounding the case.

“I question the motives of the district attorney of Alameda in filing these cases without properly vetting the evidence against these officers,” said Cardoza, who represented two of the officers charged in the sex scandal.

O’Malley announced in September 2016 that she would charge seven officers, but later declined to file charges against one. At the time, she said her investigators had meticulously examined the evidence and believed the charges would be proven beyond a reasonable doubt.

Teresa Drenick, a spokeswoman for the district attorney’s office, said the office stands behind its work.

“The district attorney’s office stands behind the criminal charges we file,” she said. “We wholeheartedly believe the evidence supports those charges.”

The scandal centered on contact police officers and sheriff’s deputies had with an Oakland police dispatcher’s daughter, who at the time of the events was a Richmond teenager and self-described sex worker.

The young woman who previously used the alias Celeste Guap, but now goes by her first name, Jasmine, told The Chronicle last year that 29 Bay Area law enforcement officers had sex with her, some while she was a minor. On some occasions, they tipped her off about antiprostitution stings or ran names of people she knew through confidential databases, she said.

Oakland investigators first became aware of the accusations when Officer Brendan O’Brien committed suicide in September 2015 and left a note alluding to the conduct. Over the next six months, then-Police Chief Sean Whent and his top commanders conducted a careless, hasty investigation that dismissed and blamed Jasmine, according to a report by investigators later appointed by a federal judge to review the case.

The Oakland City Council in May voted to give Jasmine just under $1 million to settle the claim her attorneys had filed against the city.

O’Malley’s decision to charge four Oakland police officers has been repeatedly cited by city officials as evidence that justice and accountability ultimately prevailed.

“There was an enormous amount of misconduct by law enforcement, some of it criminal, some of it noncriminal. There was a lot going on, and I don’t know if the district attorney knew everything from the outset,” said defense attorney Dirk Manoukian, who represented former Oakland Officer Brian Bunton, whose case was dismissed.

Of his client, Manoukian added, “While it was an unbelievably poor decision, there was no criminal conduct, and ultimately the judge agreed with us. ... It wasn’t some tricky, good lawyering tactics or anything like that — the case was dismissed because there was just not the evidence to support it.”

All but one of the cases have wrapped up in Alameda County Superior Court:

• Bunton: Judge Jon Rolefson dismissed the case Sept. 13 against the 41-year-old who was charged with obstruction of justice and engaging in prostitution. Bunton had been accused of warning Jasmine about an imminent undercover operation targeting prostitution, although a lieutenant later testified there was no such sting that day. Rolefson said there was insufficient evidence to show that anything — information, in this case — was exchanged for sex. Manoukian wouldn’t say whether Bunton is seeking to get his job back.

• Ricardo Perez: Rolefson dismissed the case Wednesday, saying there was insufficient evidence to show that the former Contra Costa County sheriff’s deputy knew Jasmine was a juvenile or that their contact occurred in a public venue. Perez, 29, had been charged with unlawful sexual intercourse and oral copulation with a minor as well as engaging in lewd conduct in public.

• Giovanni LoVerde: Deputy District Attorney Sabrina Farrell on Thursday dropped the charges — felony oral copulation with a minor and lewd conduct in public — against the Oakland officer, saying the facts were similar to those of the Perez case. The 34-year-old LoVerde remains employed with the Police Department.

• Daniel Black: The former Livermore police officer struck a plea deal in February that erased all but one charge against him — misdemeanor lewd conduct in public — to which he pleaded no contest. Five other counts were dismissed. If Black, 50, doesn’t commit a crime and obeys the terms of the plea bargain — which include staying away from the young woman and steering clear of any areas where prostitution is known to occur — through May, the charge against him will be dismissed.

• Leroy Johnson: The retired Oakland police sergeant, whose alleged conduct was among the least severe, has gotten the harshest punishment: He pleaded no contest in January to a misdemeanor charge of failing to report child abuse. The plea deal for the 51-year-old, who now lives in Texas, landed him with three years of court probation and standard fines totaling $390.

• Terryl Smith: The former Oakland police officer charged with five misdemeanor counts for illegally using a criminal database and sharing the information with Jasmine has his trial scheduled for Feb. 5. His defense attorney had sought to dismiss the charges, saying in one motion the complaint against the 31-year-old was “completely devoid of any details.”

Civil rights attorney Pamela Price, who previously represented Jasmine and is seeking to unseat O’Malley next year in the district attorney race, said the “initial misinvestigation” by police had an impact on the outcomes in court. She said that an independent prosecutor such as the state attorney general’s office should have stepped in, given the scope of allegations and number of Bay Area jurisdictions involved.

“The lack of accountability creates distrust in the general public and in the department itself,” Price said. “Officers now won’t feel confident reporting misconduct when the ultimate outcome is no consequences and no accountability.”

Kimberly Veklerov is a San Francisco Chronicle staff writer. Email: kveklerov@sfchronicle.com Twitter: @kveklerov