1. There are some asylum seekers who lie about how old they are. [0] Quite a lot of them. [1]
2. The onus is on the government to show they are lying. If the government still doubts their claim but can't show otherwise with evidence, they are required to give the asylum seeker the benefit of the doubt. [2] [3] This occasionly leads to some obvious adults being sent to school as if they were children [4] [5]
3. The asylum seeker can refuse consent to invasive procedures like dental age estimation.
I imagine the UK government thinks it can use this age-checking system in the same way American police officers can use drug-sniffing dogs to indicate "probable cause" to search a vehicle.
The problem will be the false positives such a system produces -- actual children, not believed to be children, [6] because the Home Office will now have a device that can say "no" for them, and they'll use their own biases for when to accept its answer, and when not to.
We saw a very similar problem happen in the Netherlands when their civil service introduced an AI-based risk-scoring system for judging the legitimacy of child benefit claims. While it was intended to combat organised fraud, which was rife, it hit geninue claimants the hardest. It reified the biases of the civil servants, who were most skeptical about migrant and dual-nationality parents. It was an absolute disaster and was scrapped. [7]
[0] https://www.bbc.co.uk/news/articles/c4g9qjv5kleo
[1] https://fullfact.org/immigration/child-asylum-seekers-adults... "between January 2018 and March 2022, 14,208 people who identified or were identified as unaccompanied children claimed asylum in the UK. During that period, 4,814 such age dispute cases were resolved. This is where Home Office staff doubt the age of the person claiming to be a child and the claimant doesn’t have reliable documentary evidence to prove their claim. In total, 2,722 people claiming to be unaccompanied children were actually deemed to be adults"
[2] https://assets.publishing.service.gov.uk/media/694954b81a2e5...
[3] https://www.express.co.uk/news/uk/2016906/asylum-seeker-23-d... "A Sudanese asylum seeker who is at least 23 years old with facial hair and a receding hairline has been declared a child by judges."
[4] https://www.thesun.co.uk/news/39449797/asylum-seeker-posed-c... "Meron Habtu came to the UK illegally aged 24 but “fooled” the authorities into thinking he was 17."
[5] https://news.sky.com/story/asylum-seeker-who-claimed-to-be-1... "Asylum seeker who claimed to be 15 and joined school is an adult. He spent six weeks as a Year 11 student in Ipswich, with fellow pupils asking: "How's there a 30-year-old man in my maths class?"
[6] https://www.bbc.co.uk/news/uk-48750708 "Between January 2018 and March 2019, [137] children were sent into adult accommodation, only for authorities to later accept they had been telling the truth about their age."
[7] https://en.wikipedia.org/wiki/Dutch_childcare_benefits_scand...