Constable John Cunningham is giving evidence in the trial of 33-year-old Weatherston's High Court trial for the murder of Miss Elliott on January 9 last year.
The officer went to the Elliott address in answer to a 111 emergency call from Sophie's mother, Lesley Elliott at 12.30pm that day. Mrs Elliott met him outside and told him her daughter was dead. She said she and the killer were in Sophie's bedroom.
Const Cunningham went into the house and up the stairs to the bedroom. The door was locked when he tried it and he called out for it to be opened or he would kick it in.
The door was unlocked and he stepped inside a small bedroom where he saw a young woman lying on the floor, her neck and upper torso covered in blood.
A man was standing near her feet and Const Cunningham asked him ''What have you done?"
The man replied: ''I killed her''.
That was said in a calm, normal tone and the male appeared calm and reserved. He did not appear shaken and looked in control of himself.
After ordering the man to lie on the floor and handcuffing him, Const Cunningham asked ''Why did you kill her''?
The man replied: "The emotional pain she has caused me over the past year''.
When asked his name, the male said ''Clay''.
''I asked what he had used and he said a knife. I could clearly see stab wounds to her throat.''
When he asked where the knife was the person said it was ''probably underneath her''.
After checking Sophie for a pulse he asked about the scissors he could see on the floor and Weatherston said he had also used the scissors ''at the end''. But when asked if he had also used a metal skewer, Weatherston said he had not.
The officer said he had seen the skewer on the floor outside the door and linked that to the wounds.
Once Weatherston was taken outside by other police, Const Cunningham spoke to him again to get his name and other details.
He noticed Weatherston's arms had blood smears and splatters up to the elbows, his face was blood spattered, there was blood on the back of both legs of the ¾ denim shorts he was wearing and there were two scratched to the left side of his neck.
When he asked if it was ''all her blood'' on him, Weatherston said ''most of it'' but a little of his.
Sophie Elliott, a 22-year-old Honours student an Weatherston's ex-girlfriend, had been stabbed or cut 216 times amd died from the effects of stab wounds to her neck and chest.
