This week, the organisation confirmed Jason Wales had been a "long-term employee" in a Christchurch store before it discovered he had been jailed for nearly four years for grooming a 15-year-old girl in a chatroom and meeting her for sex.
He was also convicted of possessing child pornography.
His former partner Stacey (not her real name) told the Otago Daily Times she had suspected Wales of cheating on her, so trawled through his laptop, where she found the objectionable files.
She was glad to see him locked up in 2008.
Last year, though, Stacey was astonished to see him posing for a photo in a community leaflet as a "furniture store team leader" for The Salvation Army.
"Shopping at a Family Store is more like coming to see family than going to a shop," Wales said in the interview.
But the shoppers and the charity had no idea of his dark history until Stacey emailed.
The charity's national director for addiction, supportive housing and reintegration services, Lynette Hutson, put the oversight down to the fact Wales had spent many years working there, likely pre-dating the current employment protocols.
He was shuffled into a non-public role and watched closely until leaving by "mutual decision" last year, she said.
Hutson stressed there had been no complaints about his behaviour during his tenure.
Last week, The Salvation Army confirmed it had launched an independent investigation in the wake of the Keats fiasco.
It would address how the dangerous predator slipped through the net and how best to avoid it happening again.
"It's absolutely got to be stopped from happening again. I can't speak strongly enough of that," Hutson said.
Keats was employed on the basis he did not have contact with the public and the probe would assess how much contact he had with the community at large.
Two sources have since confirmed to the ODT that as a driver, the rapist would spend his days collecting furniture and other items from donors' homes around the region.
A former colleague said he witnessed Keats "man-handle" the eventual victim of his offending and was shocked to later hear of the extent of his crimes.
"As far as I'm concerned, the Sallies need to give more than an apology ... They put her in harm's way," he said.
"They let him go into people's houses. How many people did they put at risk?"
Hutson was unsure whether Keats' victim had received a formal apology from The Salvation Army but said she certainly deserved one.
"We don't want to sweep it under the carpet.
"Painful and all as it is, we do want to face it and say we are so deeply sorry and we will do our best to ensure it never happens again," she said.
Despite the two cases, Hutson did not believe there were systemic failures within the organisation.
"We can only express to the public our deepest regret and our absolute commitment to strengthening processes," she said.
The independent investigation is due to be completed next month.
