Police investigating the death of a 16-year-old girl have arrested a 19-year-old man. Amber Gibson left her home in the Hillhouse area of Hamilton, South Lanarkshire, at about 9.15pm on Friday and was reported missing later that night when she did not return. Her body was discovered in Cadzow Glen park on Sunday morning. The teenager’s death was initially treated as unexplained but police launched a murder investigation on Tuesday after a postmortem. Police are trying to piece together the last movements of the teenager, who was seen in the town’s Cadzow Street at about 9.55pm on Friday. Det Supt Raymond Brown told the PA news agency: “Her family and loved ones are understandably devastated by this untimely loss, Amber was a 16-year-old girl with her future in front of her. “It’s imperative for us to understand the circumstances that led to her death, to not only provide her family with some answers but also to remove the person responsible from the community. “At this time the most important thing for us to understand is Amber’s movements across Friday evening and any information regarding her movements up to the time she was found dead in the park. “We know she was in Cadzow Street just shortly before 10pm on Friday night, which would have been busy, there would have been pedestrians, motorists and people going about their general business. “We would ask anyone in that area if they did see Amber to come forward and tell us what the circumstances in which they’ve seen her are and allow us to take that information and understand how that may assist our investigation.” It is understood the teenager was a pupil at Moore House Academy in Bathgate, West Lothian, which is privately run and cares for children aged 11 to 18 who have faced social and educational challenges. The school has been contacted for comment. Police Scotland said there will be an increased police presence in the area over the coming days and anyone with concerns can speak to local officers at anytime. The gates to the park and part of Cadzow Street were cordoned off on Wednesday as officers carried out investigations. Anyone with information is asked to call police on 101, quoting incident 1281 of 28 November, or Crimestoppers on 0800 555 111 where anonymity can be maintained.