A police officer sent to the scene of an Albion Park Rail murder 18 years ago can recount every grisly detail of the gore that greeted him.

“I  can still see the head in the kitchen sink, positioned to look at you when you came in the front door. It was positioned that way on purpose,’’ the officer told the Mercury this week.

“The eye ball was missing, the killer had cork-screwed one of the eye balls out. 

“It’s one I won’t ever forget. It  was one of the most gruesome things I have ever seen.’’

The officer’s matter-of-fact demeanor as he recounts the horror, shows his incredible ability to compartmentalise – to keep the horrific visions at bay so they can’t seep out to haunt him.

“You just have to separate…not think about these things you see as human beings.”

Others haven’t been so successful – for that day in 1998 was one that haunted many seasoned police officers and one that marked the beginning of a terrible time in Wollongong’s history.

Shopkeeper David O'Hearn lived alone the day he made the fatal mistake of opening his front door to a stranger. 

Mark Valera attacked him from behind with a wine decanter and beat him to death.

He then cut off Mr O’Hearn’s hand and used the blood to daub Satanic messages.

The killer then went home and drank with his flatmates, a dozen or so houses away.

What struck the officer most is the fact Valera spent so much time in the home.

“This man was a a bachelor, he was 59, living alone, he had no known enemies. An innocent man gardening one minute, meat the next.

“He was doing nothing wrong, there was no motive, he wasn’t related to the killer. Yet this is what he was subjected to.

“And the killer had obviously taken hours and hours to execute his plan. It is chilling when you think about it.’’

“He chopped off the man’s hand, used it to write Satan symbols on the wall. There were other things he did, just disgusting.’’

“You got the feeling he must have been sitting there just looking at what he had done.

“It was not like a frenzy, he has done specific things that would have taken time.’’

Valera would later tell police that he had no idea who Mr O'Hearn was, but that he had seen him before alone in his garden.

"I had it in my mind that I just wanted to kill someone that day," he said.

"I asked him if there was any accommodation around, like boarding houses, and he invited me inside to talk about it.

“We sat down and he offered me a drink and when he got up and turned his back I picked up this heavy, like, bottle [a wine decanter] and hit him on the back of the head..."

Worse, Valera had pencilled a list of names of people he wanted to kill in a copy of The A to Z Encyclopedia of Serial Killers. Mr O'Hearn was in the top three. Above him was Wollongong’s Lord Mayor Frank Arkell and above that Valera’s father’s name.

The murder spree had just begun.

For what happened next, see Monday's Illawarra Mercury Crime Files.

With thanks to Wollongong City Library for archive retrieval