As revealed by The Scotsman at the weekend, the 16-year-old, who had been flagged up as a suicide risk after spending most of his life in and out of care, died less than 48 hours after being remanded.
It is understood the Scottish Children’s Reporter Administration (SCRA), as well as Glasgow’s chief social work officer, wanted him to be put in a secure unit, but there were no places available.
The details of his death emerged just weeks after the parents of Katie Allan called for sweeping changes to Scotland’s penal system, including the way in which mental health is managed.
The 21-year-old student took her own life at Polmont in June amid claims she was being bullied by other prisoners and repeatedly strip-searched.
Now, Humza Yousaf has signalled that more needs to be done beyond mandatory Fatal Accident Inquiries (FAI).
He described the suicide of William Lindsay, also known as William Brown, as a “tragedy” and said there are “rightly questions being asked.”
Writing on Twitter, he said: “I will explore what can be done in the immediate term and what is more appropriate for the Fatal Accident Inquiry.”
He added: “I am meeting the family of Katie Allan shortly - the other young person referenced in the article.
“After listening to their concerns I will give details on what we intend to do to ensure we are providing the best possible care for our young people within the prison estate.”
The SCRA wanted William’s case be kept within the children’s hearing system because of his vulnerability, but were overruled by the Crown Office.
He appeared before Glasgow Sheriff Court on 4 October charged with possession of a knife, assault and breach of the peace. The sheriff remanded him to Polmont where he was found dead the following Sunday.
Scottish Labour’s health spokeswoman, Monica Lennon, said the death identified the need for change to a “broken system”. She tweeted: “Katie Allan and William Lindsay are not the first young people to die at the hands of a broken system but they must be the last. What the hell is going on at Polmont?”
The Howard League Scotland, the prison reform charity, said: “There are many lessons to be learnt here, but the most important one is that no child should be sent to prison, ever.”