On that date, Danny Lynott had arrived at Rathbraughan Park, the house he shared with Shirley and her younger sister, Samantha.
He noted that Samantha was involved in a row over the phone with mother Lisa Conroy, and as the speaker system was activated, he recalled hearing Lisa Conroy saying: "I hope Dunbar rapes you again."
Later that evening, he returned to the house after dropping his son off at his mother's home. As he approached the door, he heard Samantha Conroy shouting: "I'm going to go to jail." Inside, a harrowing sight confronted him. Samantha was "very upset, her hair was all over the place and her eyes were burnt out from crying". Shirley was similarly hysterical.
He described how, after he intervened, Samantha told him that her father Ronnie had killed Melissa Mahon and that she and her younger sister had helped to dump the body.
Yesterday, he provided an account of the alleged conversation to a hushed courtroom. He said that Samantha claimed to have seen Melissa in an upstairs bedroom of Ronnie McManus's house. She had described seeing the accused's hands over Melissa's neck and noting that "Melissa was gasping for air".
Mr Lynott would later describe to gardai that he had been told Melissa had stopped breathing before Dunbar left the room and that Samantha had tried to revive her friend.
A further sketch of the alleged events then emerged. According to Mr Lynott, Samantha claimed to have seen her father putting Melissa's body into a sleeping bag before tying it with a gent's tie. She had described driving with her father to the lake, where the body had allegedly been dumped in the water.
Furthermore, she had claimed to Mr Lynott, she had helped her father to burn Melissa's belongings. The witness explained: "She said he went out with binoculars to the lake to see if he could see the body rising in the water."
Danny Lynott immediately picked up the phone and called gardai. When Det Garda Pauline McDonagh arrived at the house that evening, she noted: "Samantha seemed like she was in a trance. Shirley was holding rosary beads." The girls then made statements at the local garda station.
It had not been the most pleasant of days in the Central Criminal Court. In the morning, the jury of six men and six women had heard evidence of the body parts that had been recovered from Lough Gill during February of last year.
It certainly made for uneasy listening for Mary Mahon, Melissa's mother. Clad in black, her face pale and strained, she sat close to one of her daughters as a member of the Garda underwater unit described the search.
Alongside bones were a sleeping bag, a gent's tie and a faded cream nightdress with a Beauty and the Beast picture on the front of it. Each were held aloft for the benefit of the jury.
Calm and poised in the witness box, Shirley Conroy displayed a maturity beyond her 18 years. She did not glance towards her father, nor did she look down towards the rear of the packed courtroom.
Asked to identify the dark blue tie that was held up for her inspection, Shirley Conroy explained: "I think this is the tie that my dad purchased in Scotland. I think I was with him when he purchased it."
In August 2006, Shirley became aware that Melissa had run away from home and was hiding in Ronnie Dunbar's house. Speaking in a soft English accent, she explained to prosecutor Isobel Kennedy: "I thought it was a little inappropriate, I don't think she should have been there. On a few occasions when I went down Melissa would be there and I made it clear she shouldn't be there."
Ronald McManus (44) also known as Ronnie Dunbar, of Rathbraughan Park, Sligo, has pleaded not guilty to murdering Melissa Mahon on a date unknown between September 14 and 30, 2006.
He also denies threatening to kill one of his daughters during the same period.