Gunfire detectors in hospitals, museums and shopping malls could slash armed response times and save lives, according to a new GLA report.
Currently trialled in the US, the smoke alarm sized detectors use heat and sound to detect gunfire, which automatically alert police, and enable armed officers to track and follow gunmen within a building.
The new technology detects where a bullet has been fired, by analysing where the sound of the gunfire came from.
The analysis is so precise that it can detect which room in a whole building a weapon has been fired.
The devices have been proposed by GLA member Roger Evans, who has written a reporting saying the detectors would be essential in a terror threat in London.
The proposed trial is estimated to cost more than £3 million, which would by around one per cent of the terrorism budget.