LINCOLN, Neb. -- The family of a murdered 15-year-old Gering, Neb., girl wants changes to the state's Amber Alert system.

The system is used to notify the public when a child is missing.

The parents and two sisters of Heather Guerrero (pictured, left) met Wednesday with Attorney General Jon Bruning . The family said that activation of the system might have allowed Heather to be found before she was killed.

No Amber Alert was issued when Heather disappeared after delivering newspapers Feb. 11. Authorities said that no one witnessed the girl's abduction and no one immediately knew for sure that she'd been kidnapped.

Authorities in Colorado and Wyoming were eventually notified and a Denver psychic was called in to help locate her.

Guerrero's body was found in an abandoned farmhouse near Lake Minatare a day after she disappeared while on her newspaper delivery route about a half-block from her home in west Gering.

Jeffrey Hessler, 24 (pictured, right), is charged with first-degree murder, kidnapping, first-degree sexual assault and felony firearms use in connection with the crime.

Hessler lived with his parents about a block away from the Guerreros. He is also accused of first-degree sexual assault in connection with an earlier attack of another 15-year-old girl as she delivered the newspapers in Scottsbluff.