PLEASANT GROVE POLICE ARE FINALLY DISCUSSING WHAT MOTIVATED MEGAN HUNTSMAN, 39, TO MURDER SIX OF HER NEWBORNS -- OVER A 10-YEAR PERIOD -- AND THEN STORE THEIR BODIES IN BOXES, IN HER GARAGE.

CAPTAIN MICHAEL ROBERTS SAYS SHE TOLD THEM SHE WAS A DRUG ADDICT... WITH NO TIME TO BE BOTHERED RAISING CHILDREN.

DNA RESULTS HAVE ALSO BEEN RELEASED, SHOWING 5 OF THE CHILDREN WERE GIRLS... AND 2 WERE SONS.

THEY WERE ALL FATHERED BY THE SUSPECT'S ESTRANGED HUSBAND, DARREN WEST.

HE HAS TOLD AUTHORITIES HE HAD NO IDEA ABOUT THE PREGNANCIES -- FROM 1996 THROUGH 2006. AND POLICE SAY, HE IS NOT CONSIDERED A SUSPECT.

HUNTSMAN IS ACCUSED OF STRANGLING OR SUFFOCATING SIX OF THE CHILDREN.  POLICE BELIEVE THE SEVENTH WAS STILLBORN.