The armed carjackings spreading fear across the Twin Cities are frequent, brazen and often violent.

Assailants are ambushing victims in grocery store parking lots, bustling intersections and, in some cases, even as motorists park in the garage of their home. Just last week in the Crocus Hill neighborhood of St. Paul, a mother had to rush to pull her child from the backseat as three armed teenagers stole her car.

The attacks are occurring almost daily in Minneapolis and St. Paul, at all hours and in many different neighborhoods. Minneapolis police have reported more than 600 attempted or successful carjackings this year, a crime they didn't even track until a few years ago because they were so rare.

The onslaught of carjackings has startled local police and crime researchers, but new data is helping them understand who is committing these crimes and why.

Minneapolis and St. Paul are among a growing number of major metropolitan areas that experienced a historic rise in carjackings last year, with cities such as Oakland, Calif.; Chicago; and Washington, D.C., reporting a record wave of attacks.

In many instances, the suspects quickly abandon the cars, sometimes within a few miles of the attack, leaving little physical damage and even less for police to investigate. As terrorizing as the attacks can be, for the teenagers it appears to be a fleeting thrill or a chance to prove their bravado, law enforcement officials and criminologists said.

The suspects also often make no attempt to sell or dismantle the cars for parts, unlike the recent rash of catalytic converter thefts.

"It's a crime of high risk and low reward," said Chris Uggen, a University of Minnesota sociology, criminology and law professor. "They aren't selling the vehicle for money. You have a 15-year-old sticking a gun in your face and not caring about what happens to them."

Many of the carjackings are being committed by teenagers or young adults, according to numerous witness accounts and law enforcement arrests. Often the suspects are too young to care about possible consequences, and their punishment as juvenile offenders is often light in the rare instances when they get caught, Uggen and law enforcement officials said.

Some crime analysts say the carjacking surge is rooted in pandemic boredom and isolation, a lack of parental supervision and even goading by friends and rivals on social media, as teens try to gain respect by showing who can steal the most expensive cars. In some cases, teens in stolen cars are posting on social media as they are joyriding around town.

Police departments are scrambling to contain these violent, swift attacks, but they are proving stubbornly difficult to prevent. Many of the carjackings occur in busy areas with plenty of witnesses, as in two recent attacks in grocery store parking lots in Edina and St. Louis Park.

The Hennepin County Attorney's Office has dedicated more staffers to prosecute carjacking cases. Meanwhile, the Hennepin County Sheriff's Office has produced a video with tips for residents aimed at preventing carjackings, urging motorists to pay attention to their surroundings, stay off smartphones when stopped and separate their car and house keys.

Law enforcement agencies are still wrestling with how best to respond when they find themselves in pursuit of carjacking suspects, who can be young, inexperienced drivers facing a rush of adrenaline in sometimes high-powered cars.

In early December, two teenagers in a stolen Mercedes-Benz SUV were killed during a high-speed chase by police in the Robbinsdale area, prompting some community leaders to call for an end to such pursuits.

The Minneapolis Police Department conducted a recent analysis of carjackings that showed that the majority of crimes are committed in the early evening between Thursday and Monday. Most of the cars are recovered, often in nearby suburban cities or at the Mall of America, the study found. Other times the suspects use one stolen car to steal another, hopscotching the metro area in various stolen vehicles.

Like homicides, police find carjackings hard to prevent since they are most always a crime of opportunity. Most often, the suspects are wearing a mask and sometimes the victims are too dazed to give a good description.

Last year, the Police Executive Research Forum in Washington, D.C., conducted a carjacking survey in Minneapolis, Chicago, New Orleans and Washington. A few common threads began to emerge, such as that the attackers spiked when kids were out of school and that a small group of teens were often involved in multiple carjackings.

"Carjackings can become much more violent than just a regular theft of a car," said Chuck Wexler, the group's longtime executive director, who has done consulting work for the Minneapolis Police Department. "The pandemic also plays a role. Courts were shut down and there is a backlog of cases. Juveniles are treated completely different than adults for their crimes."

Wexler and Uggen said they do not blame the rise in carjackings on police departments being hollowed out by huge numbers of retirements and resignations after the police killing of George Floyd and the subsequent movement to defund police.

Other researchers have noted that carjackings are also soaring in cities like Chicago and Washington, D.C., which have some of the highest numbers of police per capita in the country.

"It is true that the Minneapolis Police Department is stretched thin, but carjacking is a tricky crime to solve anywhere," Uggen said.

Though trending up sharply, the crime surge is unpredictable, rising and falling daily based on myriad factors.

Minneapolis logged 112 carjacking attempts in November — averaging nearly four a day — but that number declined in December.

The Ramsey County Sheriff's Office assigned six deputies to focus on carjackings and has arrested dozens of juveniles.

Sheriff Bob Fletcher said the carjacking spree is a natural evolution of other crime trends.

"Before carjackings, the trend was auto thefts, and that evolved into home invasions," he said. "Crimes often begin on the east and west coasts and then find their way to the Midwest."

He noted that before 2019, Minneapolis and St. Paul police rarely reported carjackings.

Fletcher worked with juvenile offenders for years and said that they have a different mentality about committing crimes. A teenager may commit several carjackings but only be charged for one and receive a light sentence because the criminal justice system is inclined to keep young people out of jail, he said.

"Part of it comes from the video game of Grand Theft Auto, and that bleeds over into real life," he said. "And they are not opposed to using force for the right car."

Fletcher said he believes that about 50 juveniles are responsible for the majority of the carjackings in the Twin Cities, and "we know who they are." He said part of the problem is that police departments are sometimes hesitant to pursue suspects in chases.

Fletcher advocates for something that some prosecutors and legislators have been reluctant to embrace, a new get-tough attitude toward violent juvenile offenders.

"We need to change the attitude with these crimes and incarcerate the suspects," he said.

Uggen, the University of Minnesota professor, said he is not convinced tough new sentences will solve the problem.

Studies have shown that juvenile recidivism isn't cured with harsher sentences, he said. He believes a focus on carjacking will eventually end the trend.

"Young people are now disconnected and isolated during the pandemic, and violent crime has increased in general," Uggen said. "Add a gun to the crime, and it's a whole new game."

Chris Herrmann, assistant professor at John Jay College of Criminal Justice in New York, said Minneapolis, Chicago and Oakland are carjacking hotspots.

Herrmann said he believes carjackings have become more popular because new key fob technology makes it hard to steal a parked car when the owner is away. He believes that has led criminals into even riskier behavior.

"For a person who studies crime, I don't get why a person would carjack a car," he said. "They are not selling the car for parts. There are always witnesses. The crime can go downhill pretty quickly. If there is a child in the backseat, it becomes a kidnapping."