YORK, Neb. -- A 40-year-old woman serving life for a 20-year-old Bellevue murder has died in prison.

Niccole Wetherell was sentenced in 1999 in the gang killing of 19-year-old Scott Catenacci at a Bellevue park along the Missouri River.

Catenacci was stabbed 57 times, a murder that authorities said involved Wetherell and five others ranging in age from 16 to 20 years old.

According to prison officials, Wetherell was being treated for an unnamed medical condition.

Under state law, whenever an inmate dies in prison, a grand jury investigation will be held.