Some were sipping coffee as grey clouds and rain persisted in the area. Police presence was minimal.
Pistorius is accused of murdering his girlfriend Reeva Steenkamp on 14 February last year.
He pleaded not guilty to the charge of murder, and contraventions under the Firearms Control Act, including possession of ammunition without a licence. He claims he mistook Steenkamp for a burglar.
The 27-year-old claims he woke up when he heard a noise from the bathroom on that day, according to opening remarks by his attorney Kenny Oldwage.
"Reeva must have gone to a toilet, [and] closed the sliding doors," Oldwage said reading from a statement.
"I [Pistorius] approached the bathroom to defend Reeva and I."
The first witness, Michelle Burger, took the stand on Monday and testified that she heard a woman's "blood-curdling" screams coming from his house on the night of the shooting.
Cross-examination of Burger was due to continue on Tuesday.
The proceedings in the wood-panelled courtroom were broadcast live on television and radio, with the initial indictment listing 107 witnesses to testify for the State.