A long standing theory, but one ballistics supports, at least in the mind of some of those who worked the case, is that Ivan Milat didn't act alone and that there were multiple shooters at several of his crime scenes.

Host Kathryn Fox sits down with one of Australia's most respected forensic experts, Gerard Dutton to understand why some think there was more than one shooter, and how specific ballistic evidence supports this.

This episode contains references to violence, if it affects you, the number for lifeline is 13 11 14.

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