A defense lawyer suggests two Mississippi girls killed their mother in self-defense and that sheriff's deputies may have questioned them improperly.

Lawyer Greg Malta spoke Tuesday following a preliminary hearing for the 14-year-old, who's held on adult murder charges in the Jan. 4 death of her mother, Ericka Hall.

A judge found enough evidence to send the case to a grand jury, but lowered the 14-year-old's bail to $100,000. She remains jailed for now.

Her 12-year-old sister is charged as a juvenile.

An investigator says the girls confessed to planning the killing in advance. Hall's sister found her shot and stabbed outside her house near Magnolia.

Relatives say Hall called deputies days earlier after one of her daughters tried to run over her with a vehicle.