Flawed AI scanner fails to detect knives in US schools.

A student was stabbed with a knife at a school in New York despite the installation of a $3.7m AI weapons detection system by security firm Evolv Technology. The system, which is used in hundreds of US schools, failed to detect the knife used in the attack. An investigation found that the system was not designed to detect knives. The company has previously claimed that its system can detect knives, but testing has shown that it is not reliable in detecting large knives. The school district has replaced the system with metal detectors, but it remains in use in other schools.