Suzanne Pilley was murdered after she ended her relationship with David Gilroy.
She had met another man through an internet dating site and “seemed happy” when he last saw her on the morning she disappeared.
Mark Brooks, 41, from Edinburgh, said she cancelled a planned meeting with him a few days before and texted him to say Gilroy had appeared as she was leaving and they had gotten into an argument.
The message read: “At least, if anything, I managed to drum through to David that it is over and to leave me alone.”
The pair met up the next day, on Monday May 3, he cooked her a meal and she stayed over. He said he dropped her off near her flat on the morning of Tuesday May 4.
“She waved and she seemed very happy. She was happy all weekend. That was the last time I saw her,” said Mr Brooks.
The 38-year-old was planning ahead before her life was brought to an abrupt end.
Colleagues said she was part of a relay team for the Edinburgh marathon to be held later that month.
She had a pet cat, Mercury, and tropical fish, and it was out of character for her not to make arrangements for them to be cared for if she was going to be away.
She was planning to go to see a film and the last text she sent was to her father asking to borrow his phone for a cinema discount code he had.
On the morning of May 4, her mother received a text message, saying: “I think Mark likes me. Take it slow.”
Ms Pilley carried out her routine journey to work and CCTV showed her arriving in the city centre.
But she never turned up at her desk in the offices of Infrastructure Managers Limited, where she had worked as a bookkeeper for two years.
For her parents, the torment of not knowing what happened to their daughter continues despite today’s guilty verdict as they have never been able to put her to rest.
Prosecutors faced an unusual and complex case to piece together without a body or direct eye witness evidence.
Stephen McGowan, district procurator fiscal for Edinburgh, said: “Having said it’s a complex case to pull together, with numerous statements and productions and experts, the case ultimately against David Gilroy and the evidence against him is devastatingly simple.”
That case is that he went to the basement of the Thistle Street office, killed her there, placed her body in a recess in the car park, went home to get his car on a pretence, brought it back and then spent his lunch hour buying some air freshener.
He then put her body in the boot, took her home and the next day took her to Argyll and put the body somewhere. Prosecutors say on the evening she was reported missing, Gilroy went to a school show and then had a family meal on Leith Walk.
The next day he drove his car back to Thistle Street before setting off on his journey to Lochgilphead.
Mr McGowan added: “The disappearance of Suzanne and the anguish it’s caused her family and friends has been unimaginable, and it’s been at the forefront of our minds throughout this.
“David Gilroy, through the evidence, is shown to be a deceitful, controlling individual. He pestered Suzanne with hundreds of text messages and then he kills her when she tells him that the relationship they had is over.
“In the immediate aftermath of the incident, the calculated steps that he takes to cover up the crime and maintain a front of normality shows a real cold personality.”