A Fresno, California, man has been sentenced by a federal judge to 18 months in prison after having pleaded guilty to firing a laser at a police helicopter.

On Monday, Michael Alvarez became the latest person to be convicted in a string of prosecutions brought by Karen Escobar, an assistant United States attorney who is believed to be the nation’s most aggressive prosecutor for such cases.

As Ars reported last November, Alvarez fired a green laser at a police helicopter shortly after midnight on October 22. The Fresno Police helicopter, Air-1, was responding to reports of a domestic disturbance as it was struck three times. The pilot, who was not named, was hit in the eyes directly each time. Air-1 then followed a car traveling northbound on Highway 99 and began to shine its searchlight directly at it. The officers aboard Air-1 radioed down to their colleagues on the ground, where they quickly located a white Toyota Corolla and started following it.

The Corolla seemingly began fleeing the officers in a chase later described in the criminal complaint. The "high-speed pursuit ended with ALVAREZ crashing his vehicle into the center divider near Floradora and First Streets. ALVAREZ exited the vehicle and ran towards 3154 E. Floradora where he was apprehended in the backyard of the residence at that location after a short foot pursuit."

Last year, the Federal Aviation Administration reported 6,771 laser strikes, or more than 18 per day, nationwide. Of those, just a tiny fraction resulted in arrests, with an even fewer number of convictions.

Federal and state authorities are generally concerned that handheld lasers, which have been getting cheaper and more powerful in recent years and are openly sold on the Web, could be used by a terrorist or a criminal to bring down an aircraft. While no aircraft in American airspace has ever been brought down (much less forced to make an emergency landing), there has been a concerted effort to identify and crack down on those carrying out such strikes.

Recently, American military pilots operating in Djibouti were warned of reported laser strikes believed to be coming from a nearby Chinese base.