SALT LAKE CITY -- Authorities say a Utah woman's motive for killing six of her newborns was that she was addicted to drugs and didn't want to deal with the responsibility.

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

Roberts said she wasn't worried about the babies' health, but simply didn't want to care for them.

Authorities think a seventh baby found in her Pleasant Grove garage was stillborn.

Police had previously declined to discuss a motive in the case.

Huntsman is in jail on $6 million bail, charged with six counts of first-degree murder.

Her lawyer Anthony Howell declined comment Tuesday.