Software that matches faces from cameras or photos against a database to put a name to a person — often without their knowledge or consent.

Cameras that photograph every passing plate and log where and when it was seen, building a searchable map of a car's movements over months or years.

Algorithms that forecast where crime will happen or who is likely to be involved, directing patrols and scrutiny toward people and blocks by statistics.

Unmanned aircraft used for aerial surveillance, crowd monitoring and, increasingly, as first responders dispatched to calls with cameras rolling.

Networks of always-on microphones on streetlights and buildings that listen for gunfire — and can capture voices — then send police to the sound.

A roster of private security cameras — doorbells, shops, homes — that residents register or connect, letting police pull footage from across the block.

Cameras worn by officers. A record of encounters that can protect the public — but also a mobile, searchable feed whose footage the department controls.

Commercial services that pool phone, location, social-media and public records into one search, letting police buy access to data they'd need a warrant to collect.

A control room fusing live camera, plate, gunshot and phone feeds onto one wall — the hub that turns scattered sensors into continuous watching.

A state or regional office where local, state and federal agencies share intelligence — pooling records on people across jurisdictions with little public oversight.