When I was working on last week’s cover story about how to build a perfect cop, one of the questions I struggled with is, How do you even define good policing?

That might seem like a common sense, no-duh type of query. We probably all feel like we know a good cop when we encounter one. But the trick, for me–as a reporter who needs to show his work–is in quantifying the difference between good and bad police work.

What are the data-driven metrics by which we can differentiate a “good” law enforcement agency from a “bad” one?

More complicated, right?

In its own annual reports, the Sacramento Police Department volunteers overall crime rates, calls for service, response times and staffing levels. While these can tell you some things about public safety in the city, it doesn’t provide the complete picture. At best, it’s like grasping an elephant’s trunk in the dark and thinking you’ve got an adequate feel of the animal.

Now, much is made of the crime rate, whether it’s dropping or rising, but that’s tied to so many different factors—jobs, housing, health care, new or changing laws, whether certain crimes are reported or even recorded—that it feels inadequate to anchor a law enforcement agency’s rep to that one umbrella category.

For instance, the crime rate dropped both locally and nationally even as agencies laid off officers during the recession, so does fewer cops mean safer streets? Probably not. Just ask Stockton.

So what else is there? I asked Francine Tournour, a former cop who runs Sacramento’s Office of Public Safety and Accountability, which monitors complaints against the city’s police and fire departments, for her take. She said it comes down to trust.

“When a controversial case happens, how does the community react?” she posed. If things erupt like they did in Ferguson, Missouri, which descended into chaos after an unarmed black man was fatally shot by a white police officer, “then you know there’s been years and years and years of this oppression and now it’s at a boiling point.”

We haven’t seen that kind of simmering reaction here, even with some questionable police shootings around the region, like the killing of a psychologically troubled military veteran in Lodi and the friendly fire death of a bank heist hostage in Stockton.

But there are gradations to the trust question, which we’ll return to in a bit.

For now, let’s examine a category that authorities rarely share with the public—clearance rates.

First, a disclaimer: Clearance rates tell us how many crimes are solved through arrests, not convictions. Even with the lower threshold, they’re not that impressive.

Nationally, law enforcement agencies cleared 36.3 percent of the 4.9 million crimes reported in 2013, according to the FBI’s National Incident-Based Reporting System. This includes 54 percent of homicides and 31 percent of forcible sex offenses, which are underreported by a staggering 80 percent estimation, according to Bureau of Justice Statistics director Bill Sabol.

The numbers are better here in Sacramento.

According to the California Department of Justice, which collects data from individual law enforcement agencies, authorities cleared 41.4 percent of the 7,515 violent crimes reported in Sacramento County in 2013, including 65.4 percent of homicides and 50. 3 percent of aggravated assaults. Robberies and forcible rapes dragged down the violent crime average with 26.5 percent and 23.5 success rates, respectively.

Some things about the numbers make sense.

For instance, in 2009, city police boasted the fewest homicides (30) and highest clearance rate (106.7 percent) of the past decade, because investigators had more time to devote to both fresh murders and cold cases, said Sgt. Doug Morse, a department spokesman.

Fewer murders to solve translates into a better batting average, while the opposite can also be true. Sacramento County cops solved the lowest percentage of violent crime (33 percent) the year that there were the largest number of reported incidents, in 2006, when agencies recorded 10,849 violent crimes, including 3,960 robberies.

But it actually doesn’t always play out this way. In fact, little about the numbers correlates the way one might expect. For instance, despite being at the peak of their staffing powers in 2008, Sacramento County law enforcement agencies actually solved fewer violent crimes—as well as non-violent burglaries and arsons—than they did after the recession.

All that means is that the current debate in City Hall about whether we need more or less cops is insanely simplistic. A better question would be, Where is public safety most vulnerable, and what resources are needed to address that?

For example, maybe we don’t need more officers on patrol, but what about additional trained investigators to shore up the department’s record on sexual assaults, property crimes and civilian complaints?

Or, considering the multiple complaints I’ve received from sexual assault victims who say they’re treated insensitively by investigators, what about hiring a trauma counselor or liaison to help conduct interviews?

Asked if solving crimes is the true measure of quality policing, Tournour says she doesn’t think so. “Because of the kind of crime that happens, the police are way behind by the time they get there,” she says.

Which is why, especially in murder cases, authorities require the cooperation of a trusting public to catch up.

As Tournour noted to me, the people in high-crime neighborhoods already have to overcome their own valid fears of retaliation in cooperating with the police. If they don’t trust that authorities have their best interests at heart, then why bother coming forward?

There’s an old saying that a cop is only as good as his or her informants. Maybe that’s the true measure of authorities’ effectiveness: How inclined are we to help them do their job?