Pepita Ridgeway earlier this week leaving court, where her husband Robert is on trial for attempted murder.
Pepita Ridgeway earlier this week leaving court, where her husband Robert is on trial for attempted murder. Liam Kidston

Gas attack trial: Mum showed holes in caravan

IT WAS "hard to believe" but prosecutors say a scientist left his mark on a caravan at the centre of a gas-poisoning trial.

Robert Wayne Ridgeway has pleaded not guilty to the attempted murder of his wife Pepita, and not guilty to an alternative charge of intentionally administering a noxious gas.

The Crown accuses Mr Ridgeway of trying to introduce enough nitrogen into a Doonan caravan to cause his wife to suffocate as she slept.

The Ridgeways had been arguing so Mrs Ridgeway was sleeping in the caravan and her husband stayed in the house.

At Brisbane Supreme Court on Thursday, jurors saw a recording of one of the Ridgeway's children giving evidence.

The child said after hearing about the alleged July 2016 gas attack, the kids "were finding it hard to believe" so Mrs Ridgeway took them out and showed them holes apparently drilled into the caravan.

Jurors also saw images of a compartment beneath the caravan floor with a hose inside.

A police officer said he saw a "green garden hose going up" and it was duct-taped.

Prosecutor David Finch has said Mr Ridgeway's fingerprints were found on the sticky side of that tape.

But defence counsel Catherine Cuthbert has suggested Mrs Ridgeway unfairly portrayed her husband as a "crazy American" gun-nut.

Jurors on Thursday heard from Senior Constable Ricky Dodds, who was alerted to the Doonan incident at about 3.15am on July 5.

Mr Dodds investigated a backpack in the attic.

Inside was a disassembled .22 rifle.

Mr Dodds said he started asking Mr Ridgeway about the caravan, when a constable appeared and said a gas cylinder had been found on the property.

Police later tested nitrogen flow rates, to simulate what allegedly happened in the caravan.

Ms Cuthbert said Mrs Ridgeway was involved during one reconstruction. Ms Cuthbert asked another police officer if he was worried that her involvement compromised the independence of testing.

The officer said it was common for both alleged victims and "persons of interest" to be involved in reconstructions where appropriate.

And he said another nitrogen test occurred without Mrs Ridgeway present.

The trial continues. -NewsRegional