Moment cop came face-to-face with 'evil' Ivan Milat

The former detective was lead investigator on the Belanglo backpacker murders has spoken out about coming face to face with serial killer Ivan Milat.

Bob Godden told A Current Affair Crime Editor Simon Bouda about the "cold shiver" he felt when he was taking hair and blood samples from Milat for DNA testing.

"I looked up and there's Ivan looking at me with those cold, sadistic eyes, and a smirk on his face," Mr Godden said.

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Even after Milat's death, Mr Godden was adamant that thoughts of the victims would always be with him.

"To be preyed on by Ivan Milat, it's just unimaginable, what they would have gone through," he said.

"(He was) pure evil, possessed with evil. A callous, cold-blooded murderer. A psychopath."

It is an assessment with which forensic psychiatrist Rod Milton agrees.

Dr Milton worked with the FBI's behavioural science unit during the investigation into the murders.

Initially, he said, he suspected there may have been two killers due to the disparity in how the victims died.

"The very deliberate nature of the killing of (Caroline) Clarke, she'd been not just shot once, but many times, from someone who sat some distance from her," he said.

"(Joanne) Walters was killed in a much more brutal, vicious fashion with a stab wound to the back of the neck."

Working with the FBI, he determined the killer was "controlling", "sadistic", and would be likely to keep trophies from his murders.

Milat was convicted of seven murders in 1996.