The prosecution is urging a Supreme Court jury in Broome to dismiss suggestions it may have been one of several Frenchmen who fatally stabbed a Pilbara mine worker.
The family of Thomas Camus have travelled from France for his trial.
The 23-year-old is accused of killing Kristopher Dixon, 32, on Christmas morning in 2011.
Mr Dixon's death outside the local nightclub was recorded in mobile footage shown to the jury.
The defence has argued the footage is too blurry to prove beyond doubt Camus delivered the fatal wound.
In their closing submissions today, prosecutors told the jury the video, DNA evidence and witness testimonies pointed overwhelmingly to the Frenchman's guilt.
Closing statements are expected to continue through to the end of the week.