SALT LAKE CITY » A Utah mother told authorities that she killed six of her newborns and stored their bodies in a garage because she was addicted to drugs and didn’t want to deal with the responsibility of raising them, police said Tuesday, revealing a suspected motive for the first time.

Megan Huntsman, 39, was heavily into a meth addiction when she strangled or suffocated the infants from 1996 to 2006, Pleasant Grove Police Capt. Mike Roberts told The Associated Press.

She wasn’t worried about potential health problems caused by her drug abuse while pregnant, she simply didn’t want to care for them, he said. "It was completely selfish. She was high on drugs and didn’t want the babies, or the responsibility," Roberts said. "That was her priority at the time."

Authorities think a seventh baby found in her Pleasant Grove garage after an April search was stillborn.

Police had previously declined to discuss a motive in the case, saying only that it had been uncovered during interviews with Huntsman.

Huntsman has been held in Utah County Jail since April 13, and her bail has been set at $6 million. She has been charged with six counts of first-degree murder and is due in court in Provo on July 21. She has not yet entered a plea.

Her lawyer, public defender Anthony Howell, declined comment Tuesday, saying office policy prevents him from discussing open cases.

Huntsman’s estranged husband, Darren West, spent more than eight years in federal prison after pleading guilty to meth charges. He was released to a halfway house in Salt Lake City in January.

West made the grisly discovery April 12 while cleaning out the garage of the home he had shared with Huntsman. He told police he found a dead infant in a small white box covered with electrician’s tape.

Six other bodies were found after police obtained a search warrant. Documents show the newborns had been wrapped in shirts or towels inside individual boxes in the garage.

West lived with Huntsman during the decade their children were killed before going to federal prison in 2006, but he isn’t a suspect in the deaths, Roberts said. Investigators don’t know how he could have been oblivious to the pregnancies or deaths, but they don’t plan to bring him in for further questioning.

Huntsman remains the only suspect in the investigation, which remains open, Roberts said. Results of a psychological examination of Huntsman haven’t been disclosed.

DNA results revealed Tuesday showed that all seven babies were full term and that five were girls and two were boys. Those tests also confirmed that West was biological father of the infants.

Previous tests from the Utah state lab found that the babies were likely dead anywhere from two to 10 years or more, Roberts said.

The day of the grisly discovery, Huntsman told police that were eight or nine dead babies in her home, a previously released search warrant affidavit showed. But Roberts said Huntsman was confused and was taking a ballpark guess. Roberts said Tuesday investigators continue to believe there were only seven.