That might have given homicide detectives vital clues - was this a burglary gone wrong? Did the killer enter looking for something in particular and ransack the home as they desperately searched for it?
He has been described as a recluse, "quiet, gentle" and someone who "wouldn't hurt a fly".
But someone hurt him.
Mr Whiteley's body was so badly decomposed, the cause of death wasn't immediately apparent. It wasn't until a post mortem earlier this week that investigators discovered the grisly truth.
It was murder.
"It was revealed that Mr Whiteley had suffered a number of stab wounds and met a violent death," Det Insp Luke Rankin.
"We're treating his death as murder."
"It wasn't apparent to us how he died, but what was obvious was he had been dead for some time," Mr Rankin said.
Police will not say if the home was broken into.
So how does a man who apparently loves the outdoors and the quiet life in Lithgow, population 21,000, die in such a violent way?
Det Insp Rankin said he'd been told Mr Whiteley was "someone who wouldn't hurt a fly".
After days of speculation in Lithgow, where townspeople whispered to themselves and online about what really went on inside the Main Road apartment, police went public on Wednesday with the confirmation Mr Whiteley was murdered. But that meant also, there was killer on the loose.
Detectives have established Strike Force Armor to investigate Mr Whiteley's death, and have called on people to come forward if they noticed any "suspicious activity" in the area round Mr Whiteley's Main Rd home.
In particular, they are interested in movements in the area about six to eight weeks ago.
Appearing alongside Det Insp Rankin at a media conference this week was Mr Whiteley's brother, Neil Whiteley.
He told media the family was shocked by the violent nature of his death.
'A QUIET LIFE'
"He lived a quiet, solitary life and would never have harmed anyone," Neil Whiteley said.
Mr Whiteley said his brother was a retired schoolteacher and enjoyed camping, bushwalking and railways - all things he could enjoy in the Lithgow, where he'd lived since 2004.
"The circumstances of his death have come as a great surprise to us and we appeal to anyone who may be out in the community who may know anything about this."
His brother's reclusive life had made it difficult to pinpoint when the death occurred.
The last known contact he had with anyone was on August 7. That was a phone call with his brother.
Det Insp Rankin told reporters: "At this stage the last contact we know someone had with him was on the 7th of August. So that's a month from when we found his body - and it's possible he was dead for right up to that time."
He asked for people to come forward who could shed light on anything connected with Mr Whiteley that could give police the breakthrough they need.
"We want help from the community - if they have information about Mr Whiteley. About his associates, his movements, his habits, any conflicts he might have in the community."
Police refused to comment when asked if Mr Whiteley was known to them.
They also wouldn't say how many times he was stabbed, or what other injuries he suffered.
A spokesman told news.com.au those questions were being dealt with as part of the homicide inquiry.
WHO COULD DO THIS, ASKS LITHGOW MAYOR
Lithgow Mayor Maree Statham told news.com.au she'd spoken to about 50 people asking about Mr Whiteley, and none knew him.
"We're all shocked, just shattered that something like that could happen to someone - and for no apparent reason."
Ms Statham said it was "bizarre" someone could fly under the radar as much as he had, and also not be noticed for so long.
"I just can't believe that. It's extraordinary that someone could be lying there and not [be missed]."
The motive for such a violent crime was puzzling, she said.
"If it was someone who had money and was broken into, or was into drugs, or not a nice person around town...But I'm at a loss, I really don't understand it."
Ms Statham was hopeful "justice will prevail" and someone would be arrested soon, so a killer was off the streets.
"It's horrendous."
A Main Rd resident told news.com.au the stabbing death of Mr Whiteley had "unsettled" the community.
"It's bad enough to hear that he died in that way, but the fact they're saying he was there the whole time and no one knew is awful," a neighbour said.
Another resident was scared a violent act has been committed so close to home.
"Frightening that there is someone out there who knows something and that they are a killer."
