What trained investigators like Gary Conyngham see is a puzzle to be solved.

One of the things you'd look at when you see the premises in that state, well, h- how has this person or these people got into the premises? And, uh, in this case, there was absolutely no signs of a forced entry So the next logical thought is, well, has someone tricked their way in here? So, you know, got in by artifice, as in rang on the doorbell and tricked their way into the premises.

Or the other possibility is, of course, someone that had legitimate access, i.e., had a key and a right to be in there, then it's obvious that that would mean that the attacker or whoever had done this would be known to the victim.

The area around Jessica Patel's property remains sealed off this morning as detectives continue the search for her killer.

In any murder investigation, one of the things we do is, uh, what's referred to as victimology, and that is looking at every aspect of the victim's lives.

So the clue might come from her lifestyle or something in her life that has triggered this, someone she knows, people she knows, someone she's had conflict with, someone...

You know, they, they literally look at every aspect of her life, from financial to family to partners.

You know, victimology quite often gives a clue as to, you know, why this has happened.

[dramatic music] So what was the cause? There was no evidence of a break-in and no sign of a struggle, leaving detectives to consider another theory.

The fact that two people are found t- together dead at or around the same time is unusual.

So there is a possibility that this could be a suicide pact, if you like.

But everything about their lifestyle showed that they were happy together.

They were making plans to sell up and move on and look forward to their retirement.

They had a grandchild, or one grandchild, another grandchild on the way.

So that would fly in the face of them taking their lives or each other's lives.

The most important element of that race, a thorough search of D'Wit's home.