Justin was found seriously injured at High Street train station around 3.45pm on Saturday, October 16.
The 14-year-old was taken to the Queen Elizabeth University Hospital where he was pronounced dead a short time later.
Police Scotland said enquiries remain ongoing following the arrest.
Members of the public can still submit information via an online portal here.
The Major Incident Public Portal (MIPP) is a website that gives the public access to a form so they can send information directly to the major incident teams based at the Scottish Crime Campus.
Police Scotland can be contacted by calling 101 and quoting incident number 2280 of Saturday, October 16.
The British Transport Police can also be contacted by texting 61016 or calling 0800 40 50 40 quoting reference 394 of 16/10/21.
Alternatively, you can call Crimestoppers anonymously on 0800 555 111.