A man who raped a pregnant woman in her own home then snatched a sleeping toddler and indecently assaulted him could serve as little as three years in prison for the 1987 crimes.

Crucial DNA evidence that sat in a freezer for nearly three decades formed the heart of the case against Epping man Andrew James Schwab.

The samples were among thousands taken by police in the late 1980s and frozen in the hope that technology would one day advance to the point where DNA could be tested.

On Thursday Schwab was jailed for six years with a minimum of three for the rape and aggravated indecent assault. He pleaded guilty to both crimes after his DNA was matched to the historical samples.

The 53-year-old has already served two separate prison terms for attacks on seven other victims during a violent sexual rampage in 1987 and 1988.