Teenagers run from scene after fatally stabbing schoolboy with sword
Home Secretary Yvette Cooper became emotional discussing Ronan Kanda, a 16-year-old murdered with a ninja sword in Wolverhampton in 2022.
A ban on ninja swords, campaigned for by Ronan's mother, has now come into effect across the UK.
Pooja Kanda, who received an OBE for her efforts, showed Ms Cooper CCTV of Ronan's last affectionate goodbye before his death by mistaken identity.
Under the new legislation, known as Ronan's Law, possession of ninja swords now carries a penalty of up to six months in prison, set to rise to two years.
The Home Office has also introduced measures requiring retailers to report suspicious sales and increased sentences for selling illegal blades or weapons to children.