Thokozile Masipa: Oscar Pistorius's Judge and Jury

South Africa does not have jury trials, so Oscar Pistorius's fate was always going to lie in the hands of one person -- Judge Thokozile Masipa.

"The decision on sentencing is mine alone," said the 67-year-old judge on Tuesday as she handed down his punishment for the killing of Reeva Steenkamp.

Masipa came to the world's most high profile murder trial having held the gavel for just 16 years -- making her a relative novice in legal terms. (Pistorius: From Olympic Fame to Jail)

She only finished studying law in her 40s, after stints as a social worker and journalist.

But her rise from a Johannesburg apartheid township to South Africa's second black woman on the bench, provided an invaluable first-person view of justice, and of injustice.

Born in Soweto on 16 October 1947, she studied at Catholic schools in Orlando East and Manzini, Swaziland, before becoming a social worker and a crime reporter.

She was once detained during an protest about press freedom during racist white rule and reportedly asked to clean a filthy cell.

She practised at the Johannesburg Bar between 1991 and 1998, when she was appointed as a judge of the "Transvaal Provincial Division" as it was then known, by then president Nelson Mandela.

- Ruthlessly challenged testimony -

Throughout Pistorius's seven month trial she has sat in judgement at the North Gauteng High Court in Pretoria, adopting a posture of stony silence.

But when it came to sentencing, she unveiled a snap shot of the ferocious intellect at work behind the unmoving red-robed facade.

On Tuesday she ruthlessly set aside testimony that was not up to scratch, describing one key defence witness's evidence variously as "slapdash", "disappointing", "sketchy," "outdated", "uninformed", "generalised", "negatively biased" and "perfunctory."

Since she was appointed as a judge in December 1998, Masipa has not shirked from handing down stiff penalties, once giving a serial rapist a 252-year prison sentence.

She has presided over criminal cases involving rape and murder, and has spoken out strongly about violence against women.

But in finding Pistorius not guilty of murdering Steenkamp, she was accused of being far too lenient. For many a conviction on culpable homicide was not enough.

"The consensus is that she hasn't got it right," said Johannesburg-based lawyer Martin Hood after the verdict.

She may yet find her verdict reconsidered by a higher court of appeal.

On Tuesday she was unflinching, lecturing the watching South African public from the bench that the country was no longer in a dark "eye for an eye" era.

"Sentencing is about achieving the right balance," between retribution, deterrence and rehabilitation, she said.

Judging by the reactions to the five-year sentence, Masipa appears to have squared the circle.

Pistorius's family, the state and Steenkamp's family all expressed their acceptance.

"She had to give him a jail term to send a message so that people understand that making mistakes like these cannot go without any consequence," said lawyer David Dadic.

"I don't think that correctional supervision or a suspended sentence would have sent that message."