Did someone just cut you off and cause an accident? Hope you have proof.

Once reserved for police vehicles, dashboard cameras — or dash cams for short — are becoming a sought-after item for civilian drivers.

Typically mounted onto a vehicle’s windshield, these small video cameras record both video and audio from a first-person perspective (in a continuous loop). While many have a small LCD screen to ensure the camera is lined up properly, most users will pop out the memory card later to view footage on a computer or television (or stream to an app over Wi-Fi).

Dash cams first became popular in countries where scams targeting drivers became commonplace (faking an injury or car damage claim) and has also been used to keep potentially corrupt law enforcement in check. But the technology has caught on worldwide, as it’s a relatively inexpensive and easy-to-install tool.

Photographic evidence can come in handy, whether it be in case of a collision, a traffic stop or a road rage incident. To capture the latter two on some models, you may have to swivel the camera around to face the driver side window.

Without a dash cam or an eye witness, it’s your word against theirs.

Some enjoy the recreational benefits of the camera as well, capturing for example, your view of a family trip through the mountains.

Already a 2.19 billion-dollar global industry, according to Grand View Research, dash cam sales are expected to jump another 15 percent by 2025.

Why It’s Time to Buy One

If you’ve been on the fence about buying a dash cam, the timing is right for a few reasons:

Price: Starting at just $35 for an entry-level dashboard camera and with no monthly fees to be concerned with, the cost of admission isn’t too steep. Sure, higher-end models are still a couple of hundred dollars, but it could pay for itself in the event of a dispute (though dash cam evidence could implicate you, too). Memory cards are also dropping in price. A 32-gigabyte SanDisk card for example is only $20. It isn’t costly to have a service (like Best Buy’s Geek Squad) hide the wiring for you, either. Because dash cams are a relatively inexpensive investment, some people have one facing behind their vehicle as well.

Video quality: Many dash cams today offer sharp 1080p “Full HD” quality. This added detail could come in handy for when you need to zoom in on a frame to analyze information (such as a license plate or a person’s face). Some dash cams can even shoot 4K quality — offering four times the resolution of Full HD — and some models include two cameras (one facing forward, one facing back) or can swivel around. Some have wide-angle lenses that capture a full 180 degrees and many offer night vision support. A good feature to look for is an embedded GPS chip, so the dash cam can “geo-stamp” the recording with a location and time.

Easy installation: Most dash cams mount to a windshield (or sometimes a dashboard or visor), and while many have a limited built-in battery, all of them plug into a USB port in the vehicle, for power, or sometimes a 12-volt (“cigarette lighter”). Because they’re connected to the car battery, typically a dash cam begins recording once the engine turns on (auto-start and auto-stop). If it requires external memory, it’s simple to pop in a microSD card once the dash cam is installed. With many dash cams, the video file is automatically saved and protected from overwriting if it detects an incident (via an internal “G sensor”).

Newer Features

Today’s dash cams have many features worth considering.

Parking mode: With these models, the dash cams go into a standby mode when the engine is turned off. But if it detects vibration, such as someone grazing the parked car or trying to break in, the camera will wake up and record for a short while. Some offer a remote live view and push notifications to your phone.

Wireless streaming: Usually for the sake of easy viewing rather than livestreaming, some of today’s dash cams can send the video footage to a companion app, to view on a smartphone or tablet, instead of popping out the memory card to view on another screen. Expect this feature to become more popular.

Collision detection: Since most dash cams are facing forward, some higher-end models can alert you if it detects the distance between your vehicle and the vehicle in front of you is getting too close, when driving at higher speeds and will alert the driver accordingly. On a related note, some models also have lane departure alerts, which alerts you when you drift out of your lane unintentionally.

Speech support: The top-of-the-line Garmin Dash Cam 65W ($349) offers voice support, so you can conveniently issue an audio command to start or stop audio recording, take a still picture, and so on. The Garmin Speak Series ($139 and up), on the other hand, also includes Amazon Alexa support, so you can ask your car to play music, create to-do lists, check your calendar, ask for weather and traffic and even control smart home devices.