The judge in the Daniel Morcombe murder trial says the case highlights arguments against tougher sentences for sex offenders.

Justice Roslyn Atkinson says she’s concerned harsher jail terms would act as a “perverse incentive” to offenders to kill their victims.

The Newman government has introduced some of the country’s toughest child sex offender laws since it came to power, including life imprisonment with a 20-year non-parole period for serious repeat offenders.

Murderers face the same minimum sentence.

The judge made her comments on Friday, just before sentencing Daniel’s killer Brett Peter Cowan to life imprisonment including 20 years without parole.

“People who call for longer sentences, harsher sentences, for sex offenders need to consider the evidence in this case, that Mr Cowan killed Daniel Morcombe to avoid detection,” Justice Atkinson told the Supreme Court in Brisbane on Friday.

“And if the sentence for a sex offence is the same as the sentence for a murder, my concern is that it would act as a perverse incentive to offenders to kill victims.

“Killing a victim is worse than sexual offending against a victim and this case is an example of that.”

Cowan had two convictions for molesting children prior to 2003, when he abducted and killed Daniel, 13, on the Sunshine Coast.

His most recent before that was in 1994 when he was sentenced to seven years’ imprisonment for the horrific sexual assault of a six-year-old boy.

The former tow truck driver served only half that term.

Queensland Attorney-General Jarrod Bleijie said the government would continue to take the toughest stance on child sex offenders.

“Everything we have done has been about preventing other families from going through what the Morcombes have had to endure,” he said in a statement.

“We want Queensland to be the safest place to raise a child and we will do whatever we can to protect the most vulnerable in our community.”