The murder trial of South African athlete Oscar Pistorius has resumed for the closing arguments after months of courtroom evidence closely followed by domestic and world media.
Prosecutor Gerrie Nel is the first to make his concluding comments. The defence is due to follow on Friday.
Mr Pistorius denies murdering his girlfriend Reeva Steenkamp.
He says he mistook her for an intruder, but the prosecution says he deliberately shot her after a row.
Ms Steenkamp was killed at Mr Pistorius’ home in South Africa’s capital, Pretoria, on 14 February last year.
Mr Nel began his closing argument by accusing the athlete’s lawyers of presenting two lines of defence that “can never be reconciled”.
Mr Pistorius said he had fired both involuntarily and also out of fear, Mr Nel argued, insisting the court had to choose only one of his defences.
He also attacked Mr Pistorius for being a “deceitful witness” and said the sprinter had dropped the “the baton of truth”.
The Olympic sprinter’s murder trial was adjourned last month for the closing arguments to start.
BBC Africa correspondent Andrew Harding says that Mr Nel will explain in detail why he believes he has proved that Mr Pistorius deliberately murdered his girlfriend.
Our correspondent says that the evidence of neighbours and forensic experts will be important – but the athlete’s own testimony is crucial.
The prosecution is convinced he gave conflicting accounts of how and why the double amputee shot Ms Steenkamp four times through his toilet door.
Judge Thokozile Masipa – a subdued presence so far – is now likely to intervene more and her questions could well provide hints about a future verdict.
Oscar Pistorius’s lawyer, Barry Roux, is expected to follow with his closing arguments on Friday.
Correspondents say the proceedings will be a final showdown between two of the country’s top legal minds.
Judge Masipa is expected to adjourn the trial after hearing the arguments to consider her ruling, a process that analysts say will take in between a week to a month.
There is no jury.
The defence will present a detailed timeline of events – and will seek to show that a disabled, panicking man convinced an intruder had broken into his home – made a terrible mistake.
If found guilty of murder, the 27-year-old, who went on trial on 3 March, could face life imprisonment.
If he is acquitted of that charge, the court will consider an alternative charge of culpable homicide, for which he could – if convicted – receive about 15 years in prison.