The grade 9 pupil from Aurora Girls’ High School went missing last week Thursday after going to a local shop.
Officers said that the suspect was arrested in White City in the early hours of Thursday morning.
Earlier this week, police handcuffed a 22-year-old man who was suspected of being one of the killers.
Police spokesperson Kay Makhubele said: “They both appeared before the Protea Magistrates Court after the second suspect was arrested in the early hours of today.”
Police said that they were searching for one more person.
Image (Police spokesperson Kay Makhubela).