'Where justice ends, mercy begins'

Yeeda Topham walks free from court. "How on earth will I be able to do it?” she wrote.

A woman who killed her baby son when she jumped from the eighth storey of a building with the boy in her arms will walk free from prison.

Following 11 months in prison awaiting her sentence, Yeeda Topham, 41, was told today she would not need to serve any more time over the death of 21-month-old James in November last year.

WA's Supreme Court heard how Mrs Topham's severe depressive illness took complete hold of her in the months leading up to her son's death, triggered by a marriage breakdown and a belief the bond with her baby had somehow broken.

Poems written by the former teacher - one entitled "What it is like to lose the bond with your baby" - spoke increasingly of her fragile mental state, described thoughts of “damaging her baby” and her fear of the “cruellest fate for her little one in being left behind”.

Despite a spell at a psychiatric hospital, and other mental health care, Mrs Topham's despair reached breaking point last November 5, beginning with an attempt to kill herself and her baby by gassing them both in her car at a property in Roleystone.

When that attempt was unsuccessful, she drove to the apartment block in West Perth where she used to live with her estranged husband, climbed an outside staircase to the eighth floor and jumped off, with James in her arms.

Both suffered catastrophic injuries, with the toddler dying soon afterwards.

Mrs Topham was originally charged with the wilful murder of James, but eventually pleaded guilty to his unlawful killing in October this year.

Prosecutor Dave Dempster told the court depression at the breakdown of Mrs Topham's marriage had been exacerbated by post-natal depression following James' birth - illustrated in her poems.

"How on earth will I be able to do it?” she wrote in one.

Defence lawyer Paul O'Brien said Mrs Topham had been aware of her depressive illness, and attempting to treat it - describing it as a "black cloud" which eventually overtook her.

Sentencing Mrs Topham, Judge John McKechnie said the choice of a building where she used to live with James' father showed an "element of vengeance".

But the judge then said any punishment he could impose would not come close to the loss of her child, and the resultant effects, and said Mrs Topham would not have to serve any more jail time.

"This is a sad case whichever way you look at it," Justice McKechnie said.

"On the day, and many months before, you were suffering a severe mental illness.

"Taking a human life can never be condoned, and there are many victims of your crime.

"But human frailty overcame all your normal inhibitions.

"Where justice ends, mercy begins."