Michael Winter

USA TODAY

A Utah mother killed six of her newborns because she was addicted to methamphetamine and couldn't cope with caring for the children, police said Tuesday.

It's the first time that authorities have cited a motive in the case of 39-year-old Megan Huntsman, who was arrested in April and charged with six counts of premeditated murder.

She is accused of strangling or suffocating the infants between 1996 and 2006 and then hiding their bodies in the garage of her Pleasant Grove home, south of Salt Lake City. Authorities believe a seventh infant they found was stillborn.

"It was completely selfish. She was high on drugs and didn't want the babies, or the responsibility," Pleasant Grove Police Capt. Mike Roberts told the Associated Press. "That was her priority at the time."

Her public defender told AP he could not discuss the case.

Roberts also announced Tuesday that DNA testing showed that all of the full-term babies — five girls and two boys — were fathered by Huntsman's estranged husband, Darren West, who was released from federal prison in January after serving eight years for having meth-making chemicals. He alerted police after finding a white box, sealed with electrical tape that contained a baby wrapped in plastic bags and a green towel. He is not a suspect.

Huntsman, who is being held on $6 million, cash-only bail, has not entered a plea. She has a July 21 court date in Provo.

Police say she has admitted killing six newborns, She initially told investigators she could not recall how many there were and estimated eight or nine, but police believe there were only seven.