BLACKSTONE, Va. — Police officers took aim this week at vehicles zipping down a runway in tests meant to convince judges that laser speed guns — increasingly popular among law enforcement — are as accurate as their radar cousins.

Through three days at the Virginia National Guard’s Fort Pickett, about an hour southwest of Richmond, the contraptions scree-ched and whined as the officers zeroed in on their targets — a variety of vehicles including, cars, trucks, a sports car and motorcycles.

The officers took turns revealing the speeds their devices recorded — whether it be a laser gun, radar, time-distance measure or other methods.

Sometimes, they all matched. Other times, one or two was off by a mile an hour.