Abstract: A method is for reconstructing a trajectory at a site by a processing server connected to cameras and having access to recordings from these cameras. The server implements a 3D visualization application based on virtual and augmented reality based on a static model of a 3D representation of the site, and a dynamic 3D representation database. The 3D visualization application is configured to determine, in the 3D visualization at a moment T0, the location of an object considered to have been left unattended by an owner, in response to a first instruction from the user, determine at least one camera which is best-positioned for displaying the object, access a recording from the camera to display the object at a moment corresponding to when the object was left unattended by an owner and activate a method for tracking the owner to determine the owner's current location.