Investigators of the killing of UK backpacker Peter Falconio took weeks to test his camper van for traces of gunshot, an Australian courtroom heard.
Joanne Lees and Peter Falconio had been driving through the outback
An officer also told the jury he did not know if tape and lip gloss found at the scene three months after the attack had been there earlier.
Mr Falconio, 28, disappeared after an ambush in the outback on 14 July 2001.
Bradley Murdoch, 47, denies murdering him and attacking and abducting his girlfriend Joanne Lees.
The court heard how the couple's camper van, found in scrub close to the scene on the remote Stuart Highway, north of Alice Springs, was not tested for gunshot powder until two weeks later on 1 August 2001.
By then it had been driven on a truck to a police garage in Alice Springs where it was dusted for fingerprints before being checked for gunshot powder.
Investigating officer, senior constable Ian Spilsbury, told the jury: "With residue from a gunshot, if it lands on a surface, in the fingerprint process you're dusting and you are going to be dusting residue off.
"When on the back of the truck, the wind, it's going to blow that residue off."
Officers failed to thoroughly search the scene, the court heard
Mr Spilsbury told the jury he did not know whether black tape and a lip balm tube found at the scene three months after the attack was there days after the alleged ambush.
Initially police only found the lip balm lid Miss Lees said she had used to loosen handcuffs with which Mr Murdoch had allegedly restrained her.
They did not search the nearby area until three months later, he said.
A photograph on 16 July 2001 showed a barren area underneath the bush and the lip balm lid.
But photographs on 15 October showed the area with more "leaf litter", tape pieces and the lip balm tube.
Asked by Grant Algie, for the defence, if someone had put the lip balm and tape there before he photographed it, he replied: "No. I was called over to the area, shown the tape, and then I found the lip balm."
Questioned whether or not he would have seen the tape and lip balm when he took photographs that July, he said he did not know.
He said he thought other officers had looked under the tree and they thought he would search the area in the days after the attack.
He told the court the police had revisited the scene north of Barrow Creek on 15 October with new recruits.
He showed the new officers to the tree where the lip balm lid was found and an officer saw two pieces of black duct tape.
Miss Lees said she had bitten the tape off her handcuffs while hiding in the bush.
After taking photographs, Mr Spilsbury found the red lip balm tube.
Asked why he did not search the scene further on 16 July, he said: "I can only put it down to we thought they (other officers) had already been there and that was all they had located.
"In hindsight we probably should have gone over it, but we did not."
The court heard Aboriginal trackers visited the scene in July but were only there for a short time.
Joanne Lees and Peter Falconio's family have been at the trial
The judge accepted an apology from newspapers who had claimed the main prosecutor had referred to him by his first name.
The article by Guardian journalist Andrew Clark, had said Mr Wild called the judge "Brian" rather than "your honour".
It was published on the paper's website with similar pieces on the Sydney Morning Herald and the Melbourne Age's websites.
Bradley Murdoch, of Broome, Western Australia, also denies charges of kidnapping and assaulting Ms Lees and threatening her with a gun.
The court has heard how Miss Lees, originally from Brighton, and Mr Falconio, from Huddersfield, were attacked after being flagged down by another motorist as they drove from Alice Springs to Darwin that night. Mr Falconio's body has never been found.
The prosecution alleges Mr Murdoch shot Mr Falconio before threatening Miss Lees with a gun to her head and tying her up with her hands behind her back, before she made her escape.
The trial was adjourned until Thursday.