Police and others who study gang activity say gangs have changed in ways that make it harder for law enforcement to keep tabs on where the gangs operate.
Gang-related violence has helped fuel an uptick in shootings and killings in north Minneapolis this year, police said, but they say the level of gang violence is hard to measure.
Minneapolis Police Lt. Bret Lindback has been a cop on the city's north side since 1987. Over the years, he's seen gangs and gang members come and go.
Lindback often supervises what are called directed patrols. Officers look for gang members and known criminals and check them for warrants or parole violations.
On a recent patrol, officers detained several young African American men outside a north Minneapolis housing complex just a few blocks away from precinct headquarters.
Lindback said there was a call that someone was selling narcotics and the young men were hanging out in the area. Three of the men were booked for trespassing, and he said one was a confirmed member of the Black P Stone gang.
Lindback said the area is home to several different gangs. They have names like the Stick Up Boys and the Taliban. Lindback said these days, the gangs are more disorganized and their members are younger than they were when he started as a cop more than 20 years ago.
Lindback said gang territory has also become more fluid over the years -- partially because of the housing crisis. As foreclosures and evictions moved people around and out of north Minneapolis, so too went gang members, maybe even to another gang's turf.
"Now they're all of a sudden moved, and they're maybe moved someplace in a completely different neighborhood where there may or may not have been a gang issue or there is a gang issue," Lindback said. "So then they're plopped down in a whole different neighborhood and [will] be in conflict with these folks."
This movement is just one factor that has made tracking gang members and their activity more difficult.
The city of Minneapolis recently completed a study of gang activity in several north Minneapolis neighborhoods.
Researchers looked at arrest reports from 2009 where the person arrested was suspected by police of being a gang member. The study found that suspected gang members were more likely to commit violent assaults and homicides than others.
But study researcher Jared Erdmann said it wasn't immediately clear if the alleged crimes were committed specifically for the benefit of a gang.
"At the scene of the crime people are probably less likely to share information related to gang involvement," Erdmann said. "Whereas once investigators start getting involved then more information might come out."
There are tough penalties for gang-related crimes. There's not much incentive for someone to admit to doing something that could result in a long prison sentence, Erdmann said.
Police officials have also been reluctant to characterize shootings and homicides as gang-related. That's because sometimes the conflicts arise from non-gang related matters -- like when two young men from different gangs fight over a (young) woman.
Erdmann said gang members are also finding ways to coordinate their activities out from under the watchful eyes of police officers. In some cases, Erdmann said they use computers at public libraries to communicate with others on Facebook and other social networking sites.
"And I don't think it's just the libraries either. Some of the youth programs that have computer access have really struggled with trying to maintain their firewalls so that kids are being safe on the internet," he said.
Gang activity thrives in places where poverty and unemployment are highest, and Erdmann said the study results are a reminder that it will take much more than the efforts of police officers to eliminate gang activity on the north side.