The sun hadn’t come up yet when Wendi Sanford Green realized her car was gone. Her electric Ford Mustang Mach-E had been parked in her northwest San Antonio driveway, charging for the night. By morning, only the unplugged charger remained.

Police say the Ford SUV theft wasn’t a smash-and-grab

It was a “relay attack,” a high-tech crime that exploits the convenience of keyless entry systems.

Detectives believe the thief used a handheld device to pick up the signal from Green’s key fob, even though it wasn’t in his hands.

Unfortunately, one of two key fobs was left inside the vehicle. That made the Mustang Mach-E an easy target. The other sat inside the house.

Security footage shows a man walking past the Ford as it lights up and unlocks

Spooked by a motion light, he steps back, then returns seconds later to unplug the charger, climb in, and drive away.

The theft, Green said, happened so fast that the only clue left behind was the dangling cable.

Relay attacks work by capturing and extending the signal from a nearby key fob so the vehicle “thinks” the key is right beside it

Once the car starts, it can be driven off quietly. No hotwiring, no brute force.

The risk grows when keys are stored close to exterior walls or, as in this case, left inside the car.

Using Ford’s mobile app, Green helped police trace her SUV to a vacant house about six miles away

Detectives collected fingerprints, a fake California plate, and even a pair of plastic glasses left behind.

Inside, Green noticed the thief had cut out her built-in wireless phone charger. That’s apparently a new twist on tech-focused car thefts.

When she drove the recovered Ford home, the navigation system startled her by resuming the route the thief had entered earlier: directions to a nearby bus stop. His iPhone was still stored in the car’s device list.

Investigators called the theft a crime of opportunity and reminded drivers that technology can be both convenience and curse

Experts recommend parking in a garage, disabling passive unlock features, and storing key fobs in signal-blocking Faraday pouches to prevent digital pickpocketing.

Green says she’s already bought those pouches for her Ford’s keys, her laptop, and anything else with a signal.