WARNING: This story deals with suicide and may be upsetting.
Wallace was 55, living alone in Greymouth, and about to stand trial on charges of indecent assault against a teenage girl, when he took his own life in March 2021, Coroner Alexandra Cunninghame ruled in a finding released on Tuesday.
In a suicide note to his father dated 19 March and entitled "my last will", Wallace denied the sexual allegations made against him and on a second page he wrote his views regarding Scott Watson's conviction for the murders of Smart, 21, and Hope, 17.
Cunninghame has prohibited the publication of a police jobsheet from the day Wallace's body was discovered, detailing the scene examination at the road worker's house and his reference to Watson's case, which is still active.
The pair were never seen again and their bodies have never been found.
Watson's lawyers will contest Wallace's controversial identification as Watson as the mystery man and forensic evidence that placed two of Hope's long blonde hairs on Watson's yacht, Blade, at a Court of Appeal hearing in May.
Wallace's credibility as the police's key witness was tested over the years after his story changed.
At Watson's 1999 trial, Wallace, who had picked Watson out of a second montage of photos supplied by police in which Watson was blinking, told the jury he recognised Watson's eyes and his "mistrusting look".
The coroner said Wallace had several social stressors in his life at the time he died.
These included that his marriage had broken up and his ex-wife had successfully taken legal action to evict him from the family home at Fernhill Pl after he stopped paying the mortgage and did not respond to her offer for him to buy her out of the house.
The couple moved to the house in Greymouth in late 2017 with the woman's three daughters after Wallace was diagnosed with stage three tonsil cancer in 2016 and had to quit work, forcing them to sell their Waikawa Bay home.
Wallace was due to leave the property at the time his trial for indecent assault was to start, on 29 March, 2021.
He had been charged with four counts of indecent assault on a girl under 16 relating to alleged offending between 2010 and 2013.
According to the Crown's allegations, Wallace put his arm around the girl, placed a hand on her breasts and cupped and squeezed them outside her clothing when she was 13.
He was also accused of putting a vibrator down her top, despite her trying to pull away several times, when she was 14 or 15.
The girl also alleged that when she was 15, Wallace touched her breasts and undid her bikini top, causing one of her breasts to come free.
Wallace pleaded not guilty to the charges but because the matter never made it to trial he is presumed innocent.
The allegations were made against Wallace to police in October 2018 leading to the breakdown of his marriage in mid-2019.
Not long after, Wallace made an attempt on his life but later told his doctor he was glad the attempt was unsuccessful.
Wallace was prescribed medication to help him sleep, trialled on a drug to reduce his low mood, and referred to community mental health.
His ex-wife obtained a protection order saying Wallace's behaviour had changed, and she had become afraid of him.
The coroner said when Wallace breached the protection order in February 2020 it made headlines as other events in his personal life had done since the Sounds murder case began.
During the first Covid-19 national lockdown, Wallace stopped paying his mortgage and by December that year he ceased treatment for depression.
A neighbour's death around that time had an effect on him, and two weeks before his death he appeared to be making a will or changes to one when he told a neighbour he planned to make the man executor of his will.
On 11 March, his ex-wife won sole right to their house and Wallace was ordered by the court to move out four days later.
Coroner Cunninghame said this upset Wallace and he refused to move out, coming to an agreement that he could stay in the house until the trial was to begin.
The day before his death Wallace helped his neighbour with a television and they drove into Greymouth together, with Wallace seeming "as cheerful as anything" according to the man.
"At 5.17am on March 19, 2021, a text message which police described as 'fairly incoherent' was sent from Mr Wallace's mobile phone," the coroner said.
It is unclear who the text was sent to.
Three days later, when the neighbour had not heard from Wallace he investigated and found him dead.
Cunninghame said she believed Wallace died soon after he wrote the farewell letter to his father, and that his death was by suicide.
Where to get help:
Need to Talk? Free call or text 1737 any time to speak to a trained counsellor, for any reason.
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO (available 24/7)
• Youth services: (06) 3555 906
• Youthline: 0800 376 633
• What's Up: 0800 942 8787 (11am to11pm)
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• Helpline: 1737
If it is an emergency and you feel like you or someone else is at risk, call 111.
