Then Harris undressed the three boys, ages 16 months, 2 and 6, and dropped them one at a time over the low railing into chilly San Francisco Bay, police say.
She knew they couldn't swim and thought she was sending them to heaven. God had commanded her to sacrifice her three boys, her most precious possessions, Harris later told psychiatrists. Passersby said she seemed dazed, disoriented.
The 23-year-old mother was arrested as she pushed an empty stroller away from Pier 7.
Harris was charged with three counts of murder and has pleaded not guilty by reason of insanity. Her trail is scheduled to begin this week; if convicted, she faces life in prison.
Now 24, Harris remains in the psychiatric section of the San Francisco County jail. Public defender Teresa Caffese calls her the rare client who "doesn't have a mean bone in her body."
Her family says Harris is mentally ill and needs to be treated in a mental institution, rather than incarcerated in a prison. But prosecutor Linda Allen says that's a decision for a jury.
Legal experts say proving legal insanity is always a tall order.
"The burden of proof is on her," said Pete Kossoris, a former Ventura County prosecutor. "She has to show that, by reason of some mental defect or disease, she didn't know the nature of what she was doing or that it was wrong."
During pretrial hearings, Harris sat in court smiling slightly, eyes downcast. She laughed and talked to herself; she sometimes rocked back and forth. At least three mental health professionals have diagnosed paranoid schizophrenia. She's also borderline mentally retarded, with an IQ of 69, according to her lawyer.
Caffese contends Harris never intended to murder her children.
"She was trapped inside an overwhelming delusion, one that kept telling her to take her kids and 'put them in the water' to send them to Jesus," Caffese said in a recent court filing. "And that is what she believes she did."
She said Harris believes her children are in heaven — her youngest now potty-trained, her eldest in school. She sends God postcards written in crayon.
The case is a tragedy, conceded Allen, the prosecutor, but added that Harris must be punished nonetheless.
"She walked around the pier and cried because she loved her children, showing that she understood she had killed them and that they were gone," Allen said in court documents. "Even if defendant thought she was sending her children to heaven, she was doing so by killing them."
Avis Harris, 43, said her daughter was an outgoing and well-behaved girl who rarely got in trouble. She regularly attended Bible study and church services, often with her grandmother.
"She was very strung out on God," Avis Harris said in a recent interview with The Associated Press, along with her sister Joyce. "She believed that God could do anything."
LaShuan Harris was 15 when she became involved with the 21-year-old man who would father her children. When she got pregnant at 16, her mother considered pursuing criminal charges against the man.
"She was happy that she was pregnant. She was thrilled," said Avis Harris. "She was doing good. I didn't want her to be a follower. I wanted her to be a leader."
It was months before Harris would allow anyone else to hold Treyshun, her firstborn. Later, her aunts took care of the boy while Harris worked as a nurse's assistant at a convalescent home.
Five years later, a second son, Taronta, was born. Harris was 21 and living on her own for the first time.
"There was a lot of stress on her at that time," Avis Harris said.
And the cracks began to show.
She saw bugs in the linens at work. She would fail to recognize her own name. She stared through people instead of at them, and giggled and laughed to herself. She stayed awake all night and talked on the phone with no one at the other end, her mother said.
Harris had her first psychotic episode in February 2004, when she tried to jump out a window, her family said. Doctors prescribed Haldol, a drug used to treat schizophrenia, but she stopped taking it.
She ended up at a homeless shelter, and she got pregnant again.
Harris' case is proof that mental illness can overcome even a mother's love for her own children, Caffese said.
Avis Harris believes the system let her daughter down. Joyce Harris doesn't know whom to blame.
"My niece is sick. She needs the help that wasn't given to her before. A tragic thing had to happen," she said. "I love and miss my nephews. On Oct. 19, four people were lost, but one is still here. Don't make her suffer because she's sick. She needs help."