Rex Dallas David Fernald cautioned the 28-year-old woman before allegedly delivering the heroin that killed her.

“You NEED to be very careful though. I know someone who died off this … last week. It is very, very good so only do a little bit at a time,” Fernald texted the woman on the evening of March 9, according to court documents.

The next morning, her family found the woman dead in her Ham Lake bedroom.

On Friday, the Anoka County attorney charged Fernald, 22, with third-degree murder, accusing him of supplying the heroin that contributed to the woman’s fatal overdose.

The victim, whom authorities did not identify, was a recovering heroin user, according to the criminal complaint. Anoka County sheriff’s deputies found a small plastic bag, a spoon and syringe in the victim’s room. An autopsy determined that she died from a mix of heroin and methamphetamine.

“It is a tragedy,” said Anoka County Attorney Tony Palumbo. “As we are seeing the purity of the heroin now being distributed increase, this is the unfortunate consequence of that intense drug.”

Detectives traced the heroin back to Fernald when they examined the victim’s cellphone records. Fernald and the victim had exchanged a series of text messages on the evening of her death, according to the criminal complaint.

The complaint says:

Fernald texted the victim around 2 p.m. on March 9: “My friend has some really good [stuff] right now and so I’m trying to sell some for him to make some money … I could have him front me some and bring it to you probably.”

Fernald texted her again at 8 p.m., saying, “I’m on my way” and “... I’m here come outside.”

The victim’s family told authorities she left the house briefly around that time.

Fernald texted her again at 3 a.m. March 10: “Why aren’t you calling me back, are you mad at me. I didn’t short you.”

Fernald will be back in court Feb. 11. Anoka County District Judge Diana Street set bail at $500,000 without conditions or $300,000 with conditions of release. If Fernald is convicted, his presumptive sentence under Minnesota guidelines would be 10 to 15 years in prison.

“Once again, heroin has affected many families, and now another child has been tragically lost,” Palumbo said. “We must come together to stop what is becoming a growing problem for our young people and our community.”