District attorneys are arguably the most powerful figures in the criminal justice system.

Their decisions determine whether a person goes to prison, or jail – or whether they’ve committed a crime at all. A DA’s powers are essentially unreviewable. According to a report by the Stanford Criminal Justice Center, there’s no law that says a DA has to pursue a given case.

Yet voters often just skip over DA candidates when they hit the ballot box. In 2002, for example, about 79,000 more residents in the county voted for governor than they did for district attorney.

At a time when the state prison population is so swollen that a three-judge panel mandated a reduction in inmates, it’s the district attorney, perhaps more than any other figure, who will continue to shape the direction of the criminal justice system in San Diego County and the state.

Voters will see three names on the ballot in next week’s June 3 election: incumbent Bonnie Dumanis, her main challenger Robert Brewer and Terri Wyatt, a retired prosecutor and political underdog. If none of the candidates earns more than 50 percent of the vote, the top two vote-getters will face a runoff.

The last time the race for San Diego County’s district attorney actually had more than one person gunning for the seat was in 2002.

Powerful donors, political action committees and other politicians grasp the power of the post. Hundreds of thousands of dollars have already been pumped into the candidates’ campaigns.

For example, Sycuan Citizens for Good Government has already put more than $93,000 to support Dumanis. And the Deputy Sheriff’s Association of San Diego County PAC has put more than $105,000 in support of Brewer.

To be sure, tough-on-crime rhetoric is especially popular come election time, and the laser focus on Dumanis’ conviction record is evidence of that.

Brewer, meanwhile, said that when he goes to campaign events, he asks guests what the most powerful local elected position is and gets the typical answers: mayor, supervisor, sheriff.

“And I say, ‘All those people that you just said are very important people to the government, of local government,’” Brewer said. “‘There’s no one that you can elect that has the impact on people’s lives that a district attorney has – because none of those other people can indict somebody. None of those other people can put someone on death row.’”

“This district attorney’s power,” Brewer said, “is incredible.”

But a district attorney does more than usher criminals into the prison system.

In 2011, Gov. Jerry Brown signed the Public Safety Realignment Act to deflate the swollen prison population. The new law meant that many of the non-violent offenders who would otherwise have been sent to prison would be housed in county jails.

This means that the burden of housing low-level offenders that was once passed onto state prisons has shifted to the county, placing a strain on local jails and probation departments. In short, realignment adds a new wrinkle for DAs when they’re deciding how to prosecute a defendant.

Whoever winds up with the position, here are a few things to know about the post.

How the District Attorney’s Office Works

Here’s an abbreviated version of what the DA actually does. Once police arrest someone – or a warrant is issued for someone’s arrest – the DA’s office reviews the facts of the case and determines whether there’s enough evidence to move forward with prosecution.

A couple things can happen from there. The DA’s office can dismiss the case entirely, or it can determine a crime was committed, and decide whether to pursue the case as a misdemeanor – a less serious crime that can result in fines or jail time – or a felony, a more serious charge that can mean prison time.

The gears of the criminal justice system can grind slowly. If a judge allows, and if the person can afford it, they can post bond, which is basically a promise to pay if they don’t show for future court hearings. A judge can also trust that person that he or she will return, and let him or her out until the next court date.

Otherwise, that person sits in jail until the court decides his or her fate. Through it all, the DA’s office – which files more than 40,000 cases a year in San Diego County – plays quarterback for the state, and makes decisions on how the case will play out.

A deputy DA, or assistant DA, does much of the legwork on cases: reviewing the evidence, working with law enforcement officers who made the arrest, appearing at court hearings to push for convictions, or offering plea deals.

A plea deal is one of the most effective tools DAs have at their disposal. The idea is pretty simple: in order to avoid a lengthy or costly trial – and especially if there’s a chance that evidence wouldn’t support a conviction – the DA could offer the defendant a lighter sentence if he or she pleads guilty to a crime.

Steve Walker, a spokesman for Dumanis’ office, said a deputy district attorney is housed within the San Diego Police Department and is assigned to interface with law enforcement.

“We’re attached at the hip to each of these agencies,” Walker said. There can be natural tension between the district attorney’s office and police, he said, because not all cases that police bring to them are filed.

Investigators from the DA’s office can also further the case by meeting with victims or people involved in the alleged crimes. If someone has an alibi, for example, those investigators would help verify – or disprove – the story.

A large part of the office investigators’ mission is to proactively pursue cases one of the many task forces they have, including narcotics or internet crimes. What they choose to investigate often has highly political implications despite the fact that the post is generally supposed to be nonpartisan.

Dumanis has come under fire over this issue in the past, notably after former Chula Vista Councilman Steve Castaneda was acquitted of most perjury charges stemming from a botched corruption investigation.

At the time, Castaneda accused Dumanis of going after him at the behest of a political ally.

The DA as Office Manager

For 2013-2014, the district attorney’s office has a roughly $161 million budget, which is allocated by the County Board of Supervisors through various state and federal funds. The office has more than 300 attorneys and more than 100 investigators, some of whom dig into cases that have generally already been filed to see whether there is enough evidence to secure a conviction.

The district attorney, who in many ways has a highly managerial position, also sets funding priorities based on crime data and trends.

Currently, drug-related offenses account for 39 percent of the office’s felony prosecutions while burglaries, the next highest category, make up 13 percent and assault (including stalking) makes up 12 percent.

The DA as Advocate

Beyond working individual cases, a DA is also seen as an advocate for crime victims, a role that often involves urging changes to existing laws.

“When we’re talking about putting the ‘bad guys’ away, we’re talking about rapists, murderers and child molesters. We’re not talking about the low-level drug offender,” Dumanis said.

Currently, Walker said, the district attorney’s office is helping sponsor a bill that would give harsher penalties to sex offenders who remove their ankle bracelets.

Earlier this month, Dumanis won praise from Sheriff Bill Gore for helping write and pass Chelsea’s Law, which upped the penalties and tightened monitoring requirements for convicted sex offenders.

And in 2005, Dumanis helped push for Senate Bill 618, which became law in January 2006 and aimed to better allocate resources to help prisoners re-enter the community.

The goal of such programs is to be “smart on crime,” not just tough on crime, Dumanis said.