A man has been arrested in connection with the suspected fentanyl death of a 25-year-old woman at her Escondido home last month, police said.

Family members called 911 on Sept. 12 after the woman didn’t get up in the morning and was found unresponsive in her room. Officers and paramedics tried life-saving measures but she could not be revived.

Police found drug paraphernalia next to the woman’s body along with a power substance that came back as testing likely to be fentanyl. The medical examiner’s office did an autopsy, and officials are running toxicology tests to determine more about her death, said police Lt. Ryan Hicks.

Detectives wanted to find out where the illicit drug had come from and, last Thursday, they searched a home on Paula Way near Belknap Way in Escondido. At the home, police seized fentanyl and paraphernalia consistent with narcotics sales, Hicks said.

They arrested a 25-year-old man who police said was a gang associate. He was booked into federal custody on suspicion of possession of a controlled substance for sale, Hicks said.

Police said they believe he is the source of the fentanyl taken by the dead woman.

A 30-year-old man inside the home also was arrested after he was found to allegedly have a gun in his possession. He was booked into Vista jail on suspicion of being a felon in possession of a firearm, police said.

Hicks said police work “aggressively” to identify and hold accountable those who “participate in the poisoning of our community” through selling fentanyl. He said the department got crucial support from the county district attorney’s office and federal agencies.