The parents of murdered Queensland teenager Daniel Morcombe say they knew Brett Cowan had taken their boy when he walked into a coronial inquest.

When Brett Peter Cowan walked into the coronial inquest into the disappearance of Daniel Morcombe, the missing teenager’s mum believed she was looking at the man responsible.

And on Friday, when the serial pedophile was sentenced to life with a 20-year non-parole period for murdering the shy Sunshine Coast boy, she wanted to scream.

“I just knew I couldn’t do that. I said `yes’ and I turned around and saw (husband) Bruce’s eyes watering, (sons) Dean and Bradley were in tears,” Daniel’s mother Denise told the Nine Network.

“I still can’t believe it.”

For years, Denise and Bruce had searched for Daniel, who went missing while on his way to a Sunshine Coast shopping centre on December 7, 2003, two weeks before his 14th birthday.

They spoke to pedophiles, scoured mud and scrub on their hands and knees and read meticulously the detailed police investigation files.

“Over the journey, people fed us some shocking lies,” Bruce said, with Denise adding they heard “so many different stories of what happened to Daniel.”

“Drugged, smashed with a steel bar, under bushes, hidden under excavators, hundreds of different things.”

In 2010, they convinced the Queensland coroner to hold an inquest.

The coroner, unlike police, could use their powers to compel testimony from the long list of suspects in Daniel’s disappearance.

“We thought that was the right way to go and it proved a game breaker,” Bruce said.

Seven years after he had abducted and killed Daniel, Cowan was called before the inquest on March 31, 2011.

“As Cowan was walking into the court room, I just got a really cold shiver and the whole court room just went `oh my God’ and I turned around to Bruce and I went `oh my God, that’s, that’s him.

“And he was just horrible, it was horrible.”

Cowan was hammered by a lawyer during the inquest but told the coroner he hadn’t taken Daniel.

He was interested in younger boys.

“He said Daniel was 13 years old, he liked six to eight-year-old boys, so he wouldn’t have done it,” Denise said.

Cowan was then flown to Perth, where he was living at the time.

On this plane he met Joe, an undercover cop whose team would induce a confession to Daniel’s murder after a sophisticated five-month covert operation.

“It was absolutely remarkable. Who would have thought such a whacky covert operation would work like that?” Bruce said.

Daniel’s parents said the judge delivered a “substantial penalty” to Cowan, adding that he will be in jail “forever.”

“He’ll die in jail,” Bruce said calmly.

“I was happy with that. Hopefully he’s dead by the time he’s 60 so we won’t have to worry about the non-parole period,” Denise said.

After all the years of searching and dealing with Daniel’s disappearance and eventual murder, Denise said she feels like they have “got justice”.

“We’ll go and visit Daniel on the weekend and let him know,” she said.

“We’ve made a promise to him and … we don’t break promises.”