A 15-month investigation culminated Thursday in the bust of a Twin Cities heroin ring with ties to Mexico.

Minneapolis police headed the bust, which involved 13 people in total, according to police spokesman Sgt. Bill Palmer. Local and federal law enforcement arrested seven people Thursday in Apple Valley, Burnsville, Bloomington, Richfield and Minneapolis, as well as one the night before during a traffic stop in Burnsville. Three other suspects were already in custody for other offenses not related to the bust. Two were still on the loose Friday.

Many of those arrested were related to each other and affiliated with the Gangster Disciples, Palmer said. The group was being supplied by a Mexican crime organization out of Chicago, he said. The heroin it was selling was determined to be 70 to 90 percent pure compared to most heroin bought on the street, which is typically only 30 to 50 percent pure, Palmer said. Most new users wouldn't be able to tolerate that level of purity, he said.

During the sting, police recovered $11,000, two guns, several vehicles and about 3 ounces of gray powdered heroin, which was worth $17,000 and equal to about 800 hits.

"That's a big number of overdoses we prevented and a big number of lives we saved," Palmer said.

Palmer said it all started with one traffic stop that "snowballed" into the 15-month investigation, led by the Fifth Precinct community response team who worked with the Drug Enforcement Administration task force.

During the investigation, undercover officers purchased heroin from dealers about 20 times, which led to the bust, Palmer said. Hennepin County complaints for several of those arrested chronicle how several informants pointed the officers to the operation. The officers' purchases helped them identify members and figure out their methods.

The group was selling much of the heroin out of vehicles, a practice called "mobile dealing." According to the complaint, many of the vehicles were rentals.

Eventually, the officers were able to find out where the members lived, and they applied for search warrants on July 6.

Southwest Minneapolis' Fifth Precinct has been plagued by heroin overdoses, Palmer said. The community response team interviewed users, looked for heroin-related incidents and solicited tips from the public about suspicious vehicles, which helped the investigation.

"Taking this crew out, hopefully we'll be able to save lives," he said.

Those in custody were charged with either first-degree sale of controlled substance, first-degree conspiracy to distribute or first degree aiding and abetting the distribution of controlled substances. One or two of them may be taken into federal custody, Palmer said.

He said law enforcement worked with the Hennepin County Attorney's Office throughout the investigation to make sure they got what they needed for a successful prosecution.

In Minneapolis, there have been 10 overdose deaths related to heroin so far this year. Palmer said it would be difficult to tie this drug ring directly to those deaths, but there might be some anecdotal evidence that links them. According to reports, deaths caused by heroin overdoses in Hennepin, Ramsey and Anoka counties nearly tripled in 2011 compared to the year before. Test results have shown that heroin purchased in the Twin Cities is 93.5 percent pure -- the highest potency in the country.

This trend played a role in the police's pursuit of the drug ring as they felt strongly that it qualifies as a public safety issue, Palmer said. Just last week, Fifth Precinct police found a man on the street with a needle hanging from his arm and suffering from an overdose who had evidently been dropped out of a car, Palmer said. He said police in the area have seen several such incidents recently, in which they discover people slumped in a car or lying on the street, suffering from an overdose.

"Certainly that was part of the initiative to take this case this far," Palmer said.

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