A firearms specialist has testified that Oscar Pistorius had a good knowledge of the rules of using a gun and dealing with intruders.
The trial entered its third week on Monday with the Paralympic athlete denying the premeditated murder of Reeva Steenkamp last year, claiming he mistook her for an intruder.
The prosecution claim Mr Pistorius intentionally shot Ms Steenkamp after an argument at his house in the early hours of Valentine's Day 2013.
Sean Patrick Rens sold a Smith and Wesson 500 to Mr Pistorius after meeting him through a mutual friend in 2012. Mr Rens is is an assessor for firearm licenses.
Mr Rens read out the competency questionnaire and the examination given to Mr Pistorius upon his application to be issued with a firearm.
The South African Olympian answered every question correctly, including one about when you are legally allowed to shoot an intruder.
"There is no security gate between you and the burglars. They are armed and they advance towards you. Can you discharge your firearm because you fear for your life?," one question read.
Mr Pistorius replied: "Yes".
The next question was: "Explain the legal requirements when using a firearm for private use."
Mr Pistorius answered: "Attack must be against you, it must be unlawful, it must be against persons."
Another, more crucial and relevant question involved target identification to which Pistorius responded: "Always know your target and what lies behind."
Mr Rens also testified that Mr Pistorius had once told him about entering "code red", or "combat mode", after believing an intruder had entered his property. Mr Pistorius drew his gun before clearing the house and checking rooms. According to Mr Rens, it turned out to be the tumble dryer.
Another witness called today was police crime scene photographer Bennie Van Staden, whom defence lawyer Barry Roux accused of not labelling his pictures correctly.
Mr Van Staden admitted to moving some objects of the crime scene around of visibility and rejected claims that his photo timeline was jumbled and unclear.
The trial has been adjourned until Tuesday and is expected to call on more than 100 witnesses. An extension on the initial three week predication looks set to be extended.
If found guilty Mr Pistorius could face life imprisonment.