The policeman who shot dead Thato Mokoka placed the gun next to his body then ran away, the High Court in Johannesburg heard on Wednesday.

"He didn't walk away, he ran," testified a pregnant, 15-year-old friend of Mokoka, 16, who was shot dead on February 14 outside his home, allegedly by student constable Sipho Mbatha.

The police went looking for Mokoka with two youths and two women who accused him of being part of a gang called the BWA, and of having a gun.

"I heard one of the boys say Thato had a gun while we were still inside the shack," the girl, who may not be named, testified in camera.

She told the court that one of them had not got along with Mokoka.

"He didn't like Thato. He was jealous because Thato was always around girls. He didn't like me because he proposed to me and I turned him down."

She confirmed that Mokoka was part of a group of friends who called themselves the BWA (Boys With Advices).

The girl broke down during cross-examination earlier on Wednesday, when she was asked by advocate Kenneth Manyage to answer questions she said she had already answered.

She told the court she knew what she had seen that night.

On Tuesday, she identified Mbatha as the policeman who placed his foot on Mokoka and pulled the trigger.

In a statement after the incident, she described the gunman as dark, around 1.75m tall, with a big stomach.

On Wednesday, she said that although she was not sure the gunman was Mbatha, he matched her description.

Mbatha has pleaded not guilty to the murder charge. He claimed he was bending over to search Mokoka and get him to lie still when his gun accidentally went off.

The girl said she did not see Mbatha searching Mokoka.

She is the second person to testify. Mokoka's aunt Mpumi Mokoka testified on Monday.