ANDOVER, Minn - At the Anoka County Sheriff's Office, Commander Paul Sommer says they're unfortunately used to a heroin overdose over a weekend. Maybe even a death. But this past weekend was different.

"This particular incident kind of raised our hackles, because they came in so quick," Sommer said.

Six different heroin overdoses Saturday, one after another after another - from Fridley to Andover, Anoka to Ham Lake and even an Isanti resident dropping off an overdose at the Coon Rapids hospital.

"This leads us to believe we might have a single source of heroin that's causing these overdoses," Sommer said.

Sommer says its possible the batch of heroin was more potent than what the users were accustomed to.

"If they're using something at 40 percent purity, and now they get something at 80 percent purity and they use the same amount, they're likely to overdose," Sommer said.

Sommer says several of the survivors were saved by paramedics administering the heroin antidote, Narcan.

But two of the users died, making third-degree murder charges possible when authorities find the dealer.

That may be a challenge.

"The problem we're having is we don't have a sample left to test. The people who overdosed used all that they had," Sommer said.

That, and it can be hard to get surviving drug users to help police investigate.

"Yeah it's very difficult. They're not really going to cooperate with law enforcement. There are other investigative avenues we can take," Sommer said.

Since these overdoses involved two deaths, making them homicide investigations, Sheriff's authorities will be able to get search warrants if they wish to search cell phones and try to find the dealer of this deadly heroin.