They called it.

In December 2011, the Observer looked back on twenty-five years of its monthly Crime Maps and found an astonishing trend: the number of robberies, sexual assaults, vehicle thefts, and burglaries reported in Ann Arbor had fallen 70 percent between 1986 and 2010. Even when we compared five-year averages, to iron out year-to-year fluctuations, rates were down 63 percent between 1986-1990 and 2006-2010. And crime had continued to fall through 2011.

“We are having an exceptional year this year,” mayor John Hieftje said at the time. “It’s almost bound to go up next year.”

“It’s got to because it’s down so low,” agreed then police chief Barnett Jones. “Next year may be normal, which will be up.”

Just 722 crimes ended up on the Crime Map in 2011, the lowest total since we started tracking in 1986. Burglary, robbery, and vehicle theft all hit record lows–though sexual assaults rose from sixty to seventy-one, a four-year high.

To check the Crime Map numbers, we looked at its four categories plus arson, assault, and larceny using the FBI Uniform Crime Report, focusing on the ten years from 2002 to 2011 (the 2012 report won’t come out until this summer). They tell nearly the same story as the Observer’s maps. Comparing the most recent five years from 2007-2011 to 2002-2006, burglaries fell 26 percent, robberies 27 percent, and vehicle theft and arson 44 percent each.

But Hieftje and Jones’ prediction came true in 2012. Driven by big jumps in burglary and vehicle theft, the 2012 Crime Maps recorded 16 percent more crimes than in 2011, for a total of 841. Yet even after the increase, 2012’s count was lower than in all but the last three of the previous twenty-six years.

In that long view, last year’s 19 percent increase in burglaries might not seem very disturbing–2012’s count is still the fifth lowest since 1986, undercut only by the years 2008-2011. Even the 56 percent increase in vehicle thefts seems less worrying knowing that 2011’s total, seventy-eight, was the lowest in the twenty-seven years the Observer has tracked the crime. But long-term trends are no comfort to the 122 people whose vehicles were stolen last year or the 612 people whose homes were burglarized.

“The number of burglaries is a concern,” says police chief John Seto, a twenty-five-year AAPD veteran who got the post last July. “But it’s important to realize that one offender can cause significantly higher numbers, and we’ve made arrests that should have a positive effect this year.” Seto cites ten key recent arrests, including an Ypsilanti Township couple involved in seven burglaries, a different pair believed responsible for five, and an eighteen-year-old connected to three.

“The AAPD is doing a fantastic job of catching perps,” says Hieftje. “And they do it by traditional police work: investigating fences and pawnshops and tracing back to the criminals.”

Seto says vehicle thefts increased last year for the same reason as burglaries: “A few people are committing them, and when we make arrests, we solve numerous cases.”

“One of the reasons [for more property crime] is that heroin is back,” says Hieftje. “There’s a new supply available that’s much stronger than before. In Ann Arbor and Ypsilanti, there’ve been some overdoses, something we haven’t had for several years.”

After increasing in 2011, sexual assaults declined slightly last year, to sixty-nine. Seto believes the numbers are up because “there’s more education and outreach these days, so there’s more reporting. Most assaults are by someone known to the victim. It’s not that there’re more serial rapists. A couple of summers ago, there were a series of forcible sexual contacts, but those were not forcible rape.”

“Crime is down nationwide,” Hieftje points out. And compared to national patterns, “Ann Arbor’s got a good demographic for less crime: more educated and more income.” And despite last year’s increase, the mayor predicts that “crime will continue to decline, especially if the economy comes back stronger. It’s back in Ann Arbor, but people in the region are still hurting, and criminals are coming from places you wouldn’t expect, like the father-son [burglary] team from Dexter.”

The police chief agrees with the mayor. “Short-term, crime trends go up and down,” Seto says, “but there has been a sustained downward trend that will probably continue for the foreseeable future.”

Seto’s department now has 119 sworn officers, which Hieftje describes as “full strength.” The mayor doesn’t think the city necessarily needs more police. “It’s difficult to draw the line between more officers and less crime,” he says. “But we could have better service, like yesterday when [it snowed heavily and] we had to handle 290 accidents in three hours.”

“More officers would allow me to do more proactive policing and community engagement, like putting more officers downtown,” Seto says. “But any growth has to be sustainable”–meaning, the chief doesn’t want to hire more cops only if he’ll have to lay them off the next time money gets tight. And even with crime declining, he says, “we still need to maintain the numbers [of officers] because we have to take into consideration how people feel. People need to feel safe.”

How safe people feel may depend on which statistics they’re looking at. In 2008-2012, the combined number of burglaries, robberies, sexual assaults, and vehicle thefts declined 28 percent in Ann Arbor compared to 2003-2007, according to the Crime Maps. On the other hand, the combined number of cops in town, including U-M public safety officers, declined 32 percent from 254 in 2000 to 173 now.

Up for debate is how the trends interact. No doubt that’s why public safety staffing has been an issue in recent city elections. After last year’s upturn in crime, 2013 should be no exception.