Cape Town - The totality of the evidence against Henri van Breda did not exclude the possibility of an unknown assailant, defence advocate Pieter Botha argued in the Western Cape High Court on Tuesday.This was the "crisp question" for the court to decide - whether the State produced evidence which proves beyond a reasonable doubt that there were no unidentified attackers responsible for the triple murders and attempted killing of Marli, Botha said during day two of his closing arguments.The evidence makes the presence of an outsider, not only a reasonable possibility, but a probability, he said.READ: This could be Henri’s last Christmas at homeIn his heads of argument, Botha pointed out that, not all the hairs collected could be linked to the Van Bredas, and all identifiable fingerprints lifted at the scene were not accounted for in terms of the people who had responded to 12 Goske Street.He said 216 samples were collected at the house for DNA analysis and, although no unknown DNA was found, this only related to 155 samples reported on.Prosecutor Susan Galloway previously said that all were analysed, but those which do not give results – such as a suspected blood droplet on a door which didn't contain human DNA – were not reported on.Blood spatter evidence against a boundary wall, presumably emanating from the boys' room during the attack on Rudi, could also indicate it was created by an object, containing his client's brother's blood, moving close to the wall. Galloway said blood spatter expert Captain Marius Joubert had said these droplets most likely came from the boys' room, through the window, during the attack on Rudi.His client's two stab wounds were also not consistent with self-inflicted injuries, Botha argued, saying it begged the question: Who stabbed Henri?READ: Unlikely Van Breda concocted story – expertRudi, Botha said, had probably been asleep when he was hit, the attack on Martin was unexpected and there was no suggestion that Marli or Teresa had stabbed him.Galloway said two expert witnesses were of the view that the stab wounds may not have been considered as self-inflicted on their own, but in context, they were more likely to be self-inflicted.The absence of Marli's DNA on the axe head indicated that the only reasonable explanation for this was, if she was attacked with another weapon. This object, he said, had never been found, increasing the probability of the presence of a second assailant, he said.Galloway, however, countered that Joubert testified that, in order to create blood spatter, a blood source is necessary, which would form when the person is hit repeatedly in the same spot or in very close proximity. Marli, she said, was hit at six different places and the axe was already covered with blood, which may have impacted on the transfer.Considering that Van Breda had been wearing sleep shorts and socks at the time of the attacks, Botha questioned why none of his DNA was found on his family members. ALSO READ: 'Henri smoked 3 cigarettes while waiting for Marli to die' – court hearsGalloway said this was an anomaly, but added that the "absence of evidence is not the evidence of absence"."Uncontroverted" expert evidence also showed the De Zalze perimeter fence alarm was triggered at 01:37 and 03:36 the morning of the murders and could have been caused by unauthorised entry or exit to the estate, Botha argued.Galloway said that witness testimony had indicated these triggers were caused by dips in power to the fencing. There was no evidence of unlawful entry, she insisted.Judge Siraj Desai said the defence's version suggested that someone had come to "soek 'n gelukkie" by stealing from the Van Breda house, but went upstairs and committed an "unprecedented mass murder" without taking anything from the scene.He questioned the probability of this, saying the murders itself were committed "as if in a frenzy" and that the family was attacked in anger in a "highly personalised nature".Botha pointed out that the motive for the murders were not known.Van Breda, 23, pleaded not guilty to axing his parents and brother to death, seriously injuring his sister Marli, and defeating the ends of justice.He alleged that an intruder, wearing a balaclava, gloves and dark clothing, was behind the attack, and that he had heard other voices, of people speaking Afrikaans, in the family's Stellenbosch home in January 2015.Van Breda claimed that, after a fight with the axe-wielding intruder who was also armed with a knife, the man had escaped.Judgment is expected to be handed down on April 23.