Was someone else there when Mark Haines died 30 years ago? Here's what the forensic evidence from this crime scene can tell us about how Mark died, and whether or not he was alone.
Blood On The Tracks investigates the suspicious unsolved cold case of 17-year-old Mark Haines, whose body was found on the railway line outside Tamworth in January 1988.
This video is part of an ABC investigation, Blood On The Tracks. The Unravel True Crime podcast also explores the mysterious death of teenager Mark Haines.
If this video has raised any issues for you, please contact Lifeline on 131 114.
The illustrations in this video are an artist's interpretation of real evidence.
ABC News: http://www.abc.net.au/news/