Oblivious to the state trooper beside him, a driver on Monday morning picked up his phone and checked a text message at a traffic light in Minneapolis.

Trooper Nate Walton cited him for breaking the state’s law that forbids texting while driving. Score another one for the State Patrol’s latest weapon in its fight against distracted driving: the unmarked car.

The patrol announced on Monday that it has put five unmarked squad cars into service in the past week to watch for distracted drivers in Mankato, Brainerd and the metro area. Called “police interceptors,” they look like Ford Tauruses.

Distracted driving has become a major problem on Minnesota roads, authorities say. Last year alone, inattentive driving was blamed for 61 deaths and more than 7,000 injuries. In the past three months, distracted driving has been blamed for two deadly crashes, including one on July 21 in which a teen driver allegedly looking at Facebook ran a red light and slammed into another vehicle, killing Charles P. Maurer, 54, of Becker, and his 10-year-old daughter, Cassy.

“Distracted driving — primarily texting and driving — is something the public is harping on us to do something about,” said Col. Matt Langer of the patrol. “We are as tired of distracted driving as the public is.”

Nearly one in four crashes with a death or serious injury was attributed to distracted driving in the past four years, according to the Minnesota Department of Public Safety. The number of drivers ticketed for distracted driving also has risen, from 180 in 2008, when the texting-and-driving law went into effect, to more than 3,467 so far in 2015.

Drivers face a $50 fine for the first offense, and the law applies whether one is driving or stopped. The Legislature this year raised the fine to $225 plus court costs for second and subsequent offenses.

Langer said the patrol hopes that putting a few more unmarked cars on the road will get motorists to think twice before using their phones.

“It is sneaky, but we are telling the public that we are out there,” Langer said.

The unmarked squads allow troopers to get close enough to get a good look at what is going on inside other cars, Langer said.

Last week on his first shift in an unmarked squad, trooper Alan Thompson was on Hwy. 169 in Shakopee when a limousine carrying two passengers approached him at a high rate of speed. As the limo pulled even with Thompson’s unmarked squad, Thompson saw that the limo driver was flipping screens on his iPhone.

“He would have never let me get alongside of him if I had been in [a] fully marked squad and he would not have been changing pages on his iPhone,” Thompson said. “I could clearly watch him change the pages.”

That is key. Officers must themselves see that a driver is texting or otherwise illegally distracted to issue a citation. By using unmarked squads, Thompson, a 17-year veteran, said troopers will have more time to determine whether drivers are simply dialing a phone number, which is legal, vs. doing something illegal. State law prohibits reading, sending or composing text messages or e-mails, or accessing the Web while in traffic — even at traffic lights.

On Monday, Walton had enough time to watch the driver at 7th Street and Olson Hwy. tap the screen and read a text message. That was enough to prompt a traffic stop and a ticket.

“We are not out to deceive anybody. The observant person will know who I am.”