Rosa Hill, 36, and her mother, 57-year-old Mei Li of Antioch, are charged with murder and premeditated attempted murder for a Jan. 7, 2009, incident in which Selma Hill was killed at her home in the 7700 block of Peppertree Lane in Dublin and her grandson, Eric Hill, was wounded.
In his closing argument in the lengthy case, which began on April 13, prosecutor Casey Bates alleged that Rosa Hill and Li went to Selma Hill's home, where Eric Hill and his daughter also lived, as part of a plot to kidnap the daughter.
Bates said notes later recovered by police showed that Rosa Hill and Li called their plan "Operation Custody" and purchased a cache of weapons worthy of a small army, including guns, stun guns, a sword, a hammer tool, a crossbow, a throat cutter, a knife and a baton.
In addition, Bates said that when police investigated a computer that Rosa Hill and her mother used, they discovered that the two women had conducted Internet searches on how to get away with murder and how to strangle someone as well as on using deadly substances such as arsenic, cyanide, strychnine, mustard gas and ammonia.
But Hill's lawyer, Bonnie Narby, said Hill went to Selma Hill's home to check on her daughter, who was 2 years old at the time, and "had no plan to kill anyone."
Narby said Rosa Hill was concerned about her daughter because she thought her husband, Eric Hill, was molesting the young girl and he also suffered from psychological problems. Narby said Rosa Hill also was frustrated that the family court system had ignored her suspicions and instead had awarded her husband sole legal custody and 85 percent physical custody of their daughter.
Eric Hill, who was wounded in the Jan. 7, 2009, incident, has denied that he ever molested his daughter. He and his daughter lived with his grandmother.
Narby said Rosa Hill and her mother wouldn't have left any evidence behind if they really had a carefully constructed plan to kill Selma Hill and Eric Hill.
Referring to Rosa Hill and Li, Narby asked, "If this was a planned murder, why would they leave a mountain of evidence to let them be easily prosecuted?"
Narby said the fact that Selma Hill suffered 23 wounds, including injuries inflicted by a Taser, indicates that Rosa Hill killed the 91-year-old woman "in a sudden quarrel and the heat of passion," not as part of a calculated plan.
Narby said Rosa Hill "snapped and lost all control" when she tried to talk to Selma Hill about her concerns that day, and that the elderly woman had told her that she would try to stop her from seeing her daughter again.
The defense lawyer said Rosa Hill should only be convicted of voluntary manslaughter for the death of Selma Hill and should be acquitted or only convicted of attempted involuntary manslaughter for the attack on Eric Hill.
Li's attorney, Barbara Thomas, admitted that Li came to Selma Hill's house on Jan. 7, 2009, but said there wasn't a plan to kill anyone and Li only came there because her daughter asked for help and Selma Hill was already dead by the time she arrived.
Thomas told jurors that Li should be found not guilty of all the charges against her.
Hill and Li face life terms in state prison if they're convicted of all the charges against them.