With yet another prison sentence, a federal prosecutor in Fresno, California, has continued her aggressive campaign against people who fire laser pointers at airplanes.

On Monday, Pablo Cesar Sahagun was sentenced to 18 months in prison after pleading guilty to firing a one-watt laser at a Kern County Sheriff’s helicopter, known as Air-1, on February 26, 2015. That laser claims to produce a beam approximately 2,000 times more powerful than what is legally allowed.

US District Judge Dale A. Drozd said during sentencing, “This is an egregious case of a laser strike…The circumstances are inexplicable.”

According to prosecutors, Sahagun fired the laser four times at the helicopter before the sheriff’s deputies radioed down to Bakersfield police officers on the ground. They tracked down Sahagun’s car to a nearby convenience store and found the laser; the device had a label reading “Laser 301” and a warning saying “AVOID DIRECT EYE EXPOSURE.” He was charged with two counts of firing the laser and pleaded guilty to the first count.

As Ars has reported, it’s notoriously difficult for authorities to pinpoint where a laser strike originates from, particularly when pointed at a commercial aircraft. But when fired against law enforcement aircraft (particularly helicopters that can easily hold their position in the air), it is far easier.

The Department of Justice says that there have been more than 23,000 laser illumination incidents in the United States reported to the Federal Aviation Administration between 2011 and 2015. As of the first few months of the year, there have been more than 22 laser strikes reported in the United States every day.

In the federal judicial district that encompasses 34 California counties including Fresno and Kern, there were 214 reported laser incidents in 2015. Of those, and some earlier, Assistant United States Attorney Karen Escobar has prosecuted 17—she is believed to have brought the most number of such cases of any prosecutor nationwide.