Chicago is having a banner year for bank robberies.
As of Dec. 7, the city reported 198 robberies, a 70 percent increase in the past four months, according to BanditTracker Chicago. At this rate, the number likely will cross 200 by year's end and could double the 2011 record of 115.
It's not clear what's causing the jump, though the feds say hard economic times and the holidays aren't always to blame for the crimes.
"A theory we have is that winter months' attire makes it easiest for the robber to disguise himself," FBI media coordinator Joan Hyde told NBC Chicago. "The thief can wear hats, gloves, coats and masks without looking out of place."
Crimes in December have averaged at about 24 over the past 10 years. That could put the year-end total at nearly twice the number of last year's robberies, though it remains markedly less than the 2006 record of 284.
"Ultimately three out of four criminals get caught," Hyde said. "Almost 100 percent of them get convicted after arrest."
Suspects face a maximum of 20 years in prison, a high cost for an average loot of less than $1,000.
BanditTrackerChicago.com provides information and publishes bank surveillance images on bank robberies in the Chicago area. The site is run by the FBI, the Chicago Police Department and the Cook County Sheriff's office.