A police sting in Brooklyn Center snared a dealer who sold heroin to a 25-year-old woman who quickly fell into a coma and died, according to charges.

Russell L. Cage, 39, was charged Friday in Hennepin County District Court with third-degree murder and drug-trafficking. Cage remains jailed in lieu of $500,000 bail as he sought a court-appointed public defender Monday.

“These heroin dealers keep supplying the drugs that kill their customers,” County Attorney Mike Freeman said Monday. “The police will keep investigating the deaths, and we will keep charging dealers with murder until they finally realize that the cost to them is too high.”

The drug deal was made June 30 behind a McDonald’s in the 4400 block of Lyndale Avenue N. in Minneapolis. The woman, Emily P. Briones, of Chaska, overdosed and died at Abbott Northwestern Hospital July 4.

A woman with Briones during the drug sale told police that Briones soon starting vomiting in the other woman’s car, became unresponsive and was driven to the hospital.

On Wednesday, police set up a sting and had a confidential informant buy heroin from Cage in the parking lot outside the Wal-Mart on Shingle Creek Parkway in Brooklyn Center, the charging document read.

After the sale, police moved in and arrested Cage, who had nine baggies with heroin on him, the charges read.

The officer working the case on behalf of a multi-jurisdiction task force, Mike Merwin of St. Louis Park, said he’s encouraged by law enforcement’s intensified focus on pursuing murder cases against dealers who kill with heroin.

“Heroin is not just heroin anymore,” Merwin said. “There are any number of things cut into it” that makes it more deadly.

Cage’s criminal history in Minnesota includes no other violent offenses. He has three drunken-driving charges on his record, two of which were dismissed for guilty pleas to lesser charges.