Excellent NZ article on Expert Witnesses

 - and the comprehensibility of expert evidence.

http://www.stuff.co.nz/dominion-post/news/8094133/How-effective-are-expert-witnesses

In a Christchurch courtroom in May, prosecutor Brent Stanaway reminded those tasked with deciding the guilt or innocence of murder-accused George Gwaze that this was not a trial by experts but a trial by jury.
They could have been forgiven for thinking otherwise, and for being bamboozled by the complex scientific and medical argument advanced by both sides. Did the Zimbabwean vet's -year-old niece, Charlene Makaza, die from asphyxiation or overwhelming HIV infection and systemic shock following massive diarrhoea-related fluid loss? Did the traces of Gwaze's sperm get into Charlene's underpants by sinister means, or was it transferred in the wash?
The Crown called a slew of doctors and pathologists who maintained the only explanation for Charlene's death was sodomy and suffocation. The defence countered with four international experts supporting its contention she died from the HIV ravaging her body.
The one critical question the jury did not have to decide, was how 12 people with no scientific credentials could be expected to weigh conflicting evidence and agree on a conclusion when experts could not. And what would have happened to Gwaze had the defence not doggedly questioned evidence often regarded as unimpeachable?