GARDAI following a blood trail into an apartment building found a woman in only her underwear with blood all over her hands and feet.
Minutes later, a body was found in the river outside the building.
The revelations came at the Central Criminal Court, where Catherine O'Connor (37), of Bridge House, Bandon, Co Cork, denies murdering father-of-one Jonathan 'Dukie' Duke (27) on November 13, 2011.
Gardai told the court that Ms O'Connor was lying on the couch while a large pool of blood was in the centre of the floor near a coffee table.
Officers had called to the building after receiving a 999 call from a resident who said he had seen a body being thrown over a balcony.
Gardai spotted blood spatters all over the floor, stairs, walls and a light-switch in the complex.
The body of Mr Duke, a native of the town, was recovered from the River Bandon outside his home shortly after gardai arrived at the scene. He had been tied up and had more than 60 separate injuries.
A white electrical cable with the plug still attached was around his neck.
A post-mortem examination found he had died from asphyxiation, with a secondary factor being a significant loss of blood.
Mr Justice Paul Carney yesterday heard evidence from gardai who attended the scene.
Gda Kieran Murphy said he immediately spotted an AIB ATM card belonging to a Jonathan Duke beside a pool of blood outside Bridge House.
The front door of the apartment complex was ajar, and when he shone his torch into the hallway he saw a blood trail. He followed this up the stairs and then heard footsteps overhead.
As he ran up the stairs, he spotted a man he knew and a woman wearing only a vest and underwear.
The woman "stumbled" into flat 3 and the man immediately slammed the door.
Officers eventually gained access to the top-floor flat amid concerns that someone had been badly injured and needed medical attention.
"There was blood on the ground, on the walls, on the landing," said Gda Murphy.
Inside the flat, there was a pool of blood on the floor near a coffee table and what appeared to be a blood smear on the light switch.
The woman, who he now knows to be Ms O'Connor, kept interrupting gardai and was "shouting and abusive".
"I could see she had blood on her hands," the garda added.
The man, who was naked except for a blue robe, later said the blood belonged to 'Dukie'.
A second officer, Garda Ray Ryan, said of Ms O'Connor: "I noticed she had drink taken.
"I also noticed she had blood on her hands and on her feet as well."
Under cross-examination by defence senior counsel Isobel Kennedy, Gda Ryan confirmed that Ms O'Connor had told him "she had been taking magic mushrooms".
Minutes after gardai spoke to the occupants of flat 3, another officer told them a body had been found in the River Bandon underneath a stone bridge.
The trial, which is expected to last three weeks, continues on Tuesday.