Pistorius trial: Reeva Steenkamp shot in 'rapid fire' Published duration 16 April 2014

media caption Pistorius trial day 23 - in 60 secs

The girlfriend of Oscar Pistorius was shot in quick succession as she fell down, a forensics expert has told the South African athlete's murder trial.

This differs from a police ballistics witness who said there was short break between the first and second shots.

Mr Pistorius denies intentionally killing Ms Steenkamp in early hours of Valentine's Day last year.

He says he fired rapidly in fear through the toilet door after he mistook Ms Steenkamp for an intruder.

The prosecution says the 29-year-old model and law graduate was deliberately killed after the couple had an argument.

The double amputee Olympic and Paralympic athlete faces 25 years to life in prison if convicted of premeditated murder.

The trial has been adjourned until Thursday, which will be the last day before a break; proceedings will resume on Monday 5 May.

'Layman's understanding'

Forensics expert Roger Dixon, a defence witness, says Ms Steenkamp was standing at an angle to the door and that all four bullets hit her as fell to the ground.

Earlier in the trial, ballistics expert Captain Christiaan Mangena said he believed Ms Steenkamp was standing up facing the closed door when she was hit in the right hip.

He said she then fell back onto a magazine rack next to the toilet before three more bullets were fired at the door, one of which missed her.

The BBC's Pumza Fihlani in court says Mr Dixon's testimony challenges the state's version that Ms Steenkamp would have had time to scream after the first bullet and that Mr Pistorius then changed aim and continued firing.

On Tuesday, Mr Dixon told the court his tests showed that with the light out, Mr Pistorius' bedroom would have been almost completely dark on the evening of the shooting, despite a couple of LED lights.

This also supports Mr Pistorius' evidence that he did not see whether Ms Steenkamp was still in bed when he got up.

The court also heard sound recordings Mr Dixon had made - of a cricket bat striking a door similar to the one in Mr Pistorius' toilet, and of gunshots fired through the door at a distance of 60m (196ft) and 180m.

Mr Dixon seemed to struggle to tell the sounds apart, which the defence will use to cast doubt on what neighbours say they heard that night, our correspondent says.

Prosecution witnesses have testified to hearing a woman scream followed by gun shots, but the defence disputes their testimony, saying the only scream came from Mr Pistorius - after he had fired.

media caption Oscar Pistorius reads out the message in his Valentine's card from his girlfriend Reeva Steenkamp

But prosecutor Gerrie Nel has sought to cast doubt on Mr Dixon's credibility and qualifications as a forensics witness during his cross examination on Wednesday.

Mr Dixon is a geologist and university lecturer who worked as head of materials analysis at a police forensic laboratory in Pretoria for 18 years until 2012 and repeatedly said he was not a ballistics expert.

Mr Nel also sought to prove that he was out of his depth when he was testifying about marks on Ms Steenkamp's body.

He had identified one as a bruise which other pathologists had not, Mr Nel said.

At one stage Mr Dixon used the phrase "in my layman's understanding".

"Now you call yourself a layman. You see how irresponsible it is to make inferences that aren't in your area of expertise," Mr Nel replied.

Mr Dixon took the stand after seven days of testimony from the sprinter came to an end with him reading a Valentine's Day card from his girlfriend.

image copyright Reuters image caption Mr Dixon told the court that in his opinion the bullets were fired first then the cricket bat was used

image copyright AFP image caption Oscar Pistorius and Reeva Steenkamp had been dating for three months

If Mr Pistorius is acquitted of murder, the court must consider an alternative charge of culpable homicide, for which he could receive about 15 years in prison.

He also faces charges of illegally firing a gun in public and of illegally possessing ammunition, both of which he denies.

There are no juries at trials in South Africa, and his fate will be decided by the judge, assisted by two assessors.

Mr Pistorius is known as the "Blade Runner" because of the carbon-fibre prosthetics he uses on the track.