The alleged "Sunday rapist" on Tuesday admitted to being addicted to pornography and child pornography.
"It's a danger. It becomes an addiction that consumes all your time and attention," Johannes Jacobus Steyn told the High Court, sitting in the Palm Ridge Magistrate's Court in Alberton.
Steyn has pleaded not guilty to two counts of murder, 11 of rape, 10 of sexual assault, 10 of kidnapping, one of attempted sexual assault, and one of attempted kidnapping.
He said he watched a lot of pornography and child pornography. He likened the addiction to that of cigarettes and alcohol, and said it interfered with his work.
"I would get to work and watch pornography before starting my work."
Carina Coetzee, for the State, asked whether this addiction caused him to act out, to which he answered: "It leads to increased urges, yes."
She asked if he ever re-enacted what he saw in these films.
"Not necessarily," Steyn answered.
Judge Sita Kolbe asked him to explain his reply. He said he had re-enacted some of the sexual acts, but others were a bit far-fetched.
Coetzee, as she did on Monday, questioned Steyn on his movements on the days the 11 victims were attacked.
He again explained how he called in sick on October 12, 2012 and picked up a prostitute, because he was not sexually satisfied at home. Teenager Louise de Waal was kidnapped and murdered that day.
He claimed a similar alibi for the day two girls were kidnapped in Danville, Pretoria, in September 2010. Lazanne Farmer jumped out of a moving vehicle in an attempt to escape and died of her injuries.
Steyn said he picked up a prostitute along the Diepsloot road on his way home after he found none in Sunnyside or Pretoria West.
"Once again you and the so-called 'Sunday rapist' are in the same town, at the same place, at the same time," Coetzee told him.
On other days when he was in the area where girls were attacked, he said he did not go to perform his community service at the Yusuf Dadoo hospital in Krugersdorp.
Instead he met a woman at an abandoned holiday resort near Hekpoort in Maropeng.
Coetzee questioned how often he had, as Steyn described it, these "uncontrollable urges" to have sex, the reason he frequented prostitutes so often.
"A man is a man. I am generally in the mood," Steyn responded, to the amusement of the public gallery.
Coetzee questioned Steyn on the pellet gun police found at his house after his arrest.
"I had no plan with it, I just bought it... to play with."
She put it to him that most of the girls who were abducted testified that they were held at gunpoint and the description they gave closely matched the appearance of a pellet gun.