A bloodstain expert has detailed what may have happened at the scene of the alleged murder of Nicholas Dill.

Roi Gilbert, from Ontario, listed his conclusions yesterday after spending two days talking a Supreme Court jury through a slide show of images from the bloody scene.

The prosecution's case against the accused man, Andre Hypolite, is that he took drugs with Mr. Dill, 43, and his girlfriend Stacey Pike, now 37, at their home in Pearman's Hill, Warwick, early on Boxing Day morning 2004. He is alleged to have stabbed Mr. Dill in the back after Mr. Dill changed his mind about participating in a sex act with him while the three of them were in bed together.

It is further alleged that Hypolite threw a TV set at Ms. Pike and chopped her in the head when she tried to intervene by grabbing a machete. She said during evidence last week that she subsequently hit him with the machete.

Mr. Dill, she said, tried to fight off Hypolite but later made it into a kitchen / bathroom area where he lay bleeding in a tub and she tended to him.

The accused man is said to have escaped through a window after the Police were called. He denies murder and wounding Ms Pike with intent to cause her grievous bodily harm.

Yesterday, Mr. Gilbert finished off his slide show by explaining how a TV set, upended near a dresser, had a large stain on the back with blood shown by DNA tests to be Ms Pike's.

On the face of the TV set, he said, was blood "consistent with medium-velocity impact spatter. That's movement of five to 25 feet per second striking a blood surface."

Senior Crown counsel Paula Tyndale inquired: "Could a medium-velocity impact stain be caused by something striking at a surface with some force?"

Mr. Gilbert replied: "Yes, these are commonly seen at beating scenes of physical violence."

Asked by Ms Tyndale to list his overall conclusions, Mr. Gilbert said the incident started in the area of the bed, towards the head, as there was the least amount of blood there.

More activity – in terms of more blood – was visible moving around the bed and towards a dresser. There was at least one "medium velocity impact stain" near the head of the bed, said the expert, demonstrating at least one impact to a blood source on a person.

He detailed how movement could be seen going from the bedroom to the kitchen area, with a "medium velocity impact" on the TV set which appeared to have occurred either when it was upright or being held, prior to it landing upside down.

He also described evidence of a blood source being above the bath tub, then inside it. And, Mr. Gilbert said, there appeared to have been a source of blood above an opening where a window once was in the bedroom.

"It occurred when there was no window present, because it fell on top of the edge of the wall," he explained.

Finally, he listed blood stains showing evidence of movement down a path heading away from the residence. Blood on an exterior wall and the concrete path were shown by DNA testing to belong to Hypolite.

In response to questions from defence lawyer John Perry QC, Mr. Gilbert agreed that it was impossible to say which of the people at the scene – all of whom bled according to DNA testing – each of the stains came from.

The case continues.