A 24-year old man is expected to appear in court after apparently being linked to the murder and robbery of 17-year-old Michaela Booysen in Mossel Bay, police confirmed on Wednesday.Booysen, a pupil at Hillcrest Secondary School, was walking home with her boyfriend in the early hours of Sunday morning when they were accosted by three men in Asla Park.They demanded their belongings and a scuffle ensued."Michaela was hit with a pickaxe handle on the head and succumbed on the scene because of a head injury. The boyfriend was lucky to escape, but was later found … distraught and extremely traumatised by the event," said police spokesperson Captain Malcolm Pojie."The suspects fled the scene with a pair of black Nike takkies belonging to Michaela."Detectives worked around the clock and arrested three men between the ages of 17 and 24 early on Tuesday morning.Two of them were released on Wednesday as there was not sufficient evidence to directly link them to the robbery and murder, said Pojie.The 24-year-old remains in custody and is expected to make his first appearance in the Mossel Bay Magistrate's Court on Thursday.Meanwhile, three pupils who stand accused of stabbing 16-year-old Grade 10 pupil Khuselo Ndanda to death at Hillcrest Secondary School made their first appearance in court on Wednesday afternoon.Pojie said that the trio allegedly attacked Khuselo during first break, stabbing him several times in the upper body."After the vicious attack, the assailants jumped the school's fence at the back of the premises and ran away."A seriously injured Khuselo managed to reach the office block of the school where he collapsed. Paramedics transported him to hospital but he succumbed to his injuries en-route and was declared dead on arrival," Pojie said.The three would remain in custody until their formal bail application next Thursday.Pojie said they had increased visible police patrols and deployed neighbourhood watch members in the area to ensure the school environment "returns to normality".