The serial pedophile found guilty of murdering Queensland schoolboy Daniel Morcombe is set to be sentenced on Friday.

The crown prosecution argues that Brett Peter Cowan should be jailed without parole for longer than the mandatory minimum 15 years.

Jurors on Thursday found the 44-year-old father of three guilty of indecently dealing with 13-year-old Daniel, murdering him and interfering with his corpse after luring him from a Sunshine Coast bus stop on December 7, 2003.

After deliberating for almost eight hours, the jury was discharged on Thursday after reaching a unanimous verdict.

Media outlets are now able to reveal Cowan’s perverted sexual past, which includes horrific sex attacks on boys in Brisbane and Darwin in 1987 and 1993, for which he served nine years in jail.

During sentencing submissions before Supreme Court justice Rosyln Atkinson, crown prosecutor Michael Byrne QC argued Cowan deserved a longer sentence.

He cited Cowan’s previous convictions, which the jury was not told about, including the rape of boys aged six and seven.

But Cowan’s defence lawyer, Angus Edwards, argued his client deserved a more lenient sentence because he didn’t intentionally kill Daniel.

Daniel’s parents Bruce and Denise have tendered victim impact statements describing the anguish of losing their son at the hands of a child molester.

With Cowan present in the courtroom, Denise Morcombe described him as a “perverted soul” who underestimated the Morcombe family’s drive to catch Daniel’s killer.

“That was your mistake, you evil, evil, unhuman thing,” she wrote.

Cowan isn’t listed with the Supreme Court for Friday but a Department of Justice spokesman said the judge would be delivering a sentence.