Child killer assaulted in custody ahead of sentencing

A Victorian child killer, who stomped on his girlfriend's toddler after she urinated on his couch, has been assaulted in custody ahead of his sentencing hearing.

Lawyers for Mussie Debresay, who will learn his fate on Wednesday, say the former security guard will find jail time more onerous than other criminals.

Debresay was cleared of murder in September, but found guilty by a jury of the toddler's manslaughter.

Mussie Debresay. Source: 7 News

The two-year-old died as a result of blunt force trauma in May 2005, when her abdomen was compressed by a severe force doctors said couldn't have been accidental.

Police were able to charge Debresay after the victim's young brother came forward to give evidence years later, saying he saw Debresay stomping or standing on his sister because "she'd been naughty".

Defence barrister Dermot Dann QC told a Victorian court Debresay had also made a number of suicide attempts and developed a major depressive disorder during his time in custody.

Mr Dann also argued an 11-year delay in the case should count in his client's favour.

Mussie Debresay. Source: 7 News

But prosecutor Sally Flynn argued Debresay's assault on the vulnerable child was violent, brutal and deliberate.

Stomping on the child as she lay helpless on the floor was a particularly violent act, she said.

Debresay failed to seek immediate medical help, and then lied to treating doctors to try to protect himself, Ms Flynn said.

Justice Forrest said the jury accepted the toddler's injury must have been inflicted with "very significant force".

Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14. MensLine Australia 1300 78 99 78.