CHICAGO (AP) — Chicago police officials said Thursday they will put a stronger focus on prosecution and increased collaboration with other police agencies to combat a spike in carjackings.

Carjackings rose about 135% last year to 1,415 and continue at a high pace this year, with the youngest carjacker in recent attacks was about 12 years old and the average age of the offenders is between 15 and 20, police Superintendent David Brown said. The perpetrators often work in crews and are motivated either by joyriding or using the stolen vehicle to commit other crimes.

“We know who the repeat offenders are. We want to hold them accountable,” Brown said of the suspects. “We have to send a serious message.”

Chicago police this week issued alerts with similar language, warning residents and business owners about a group that has carried out carjackings in the city and several suburbs in the last week, and whose members are suspects in recent shootings on the city’s West Side.

There were 14,017 incidents of carjackings, and police arrested 11,207 suspects last year, Brown said. In the past five years, Chicago had 4,384 carjackings with 10,219 suspects arrested.

“This year, there have been 144 vehicular hijackings,” Brown said, with police arresting 104 suspects and recovering 611 guns. In addition, nine officers were shot at during the investigations of the crimes.

According to Brown, the coronavirus pandemic has had some impact on crime, but it isn’t clear exactly what that impact is. Carjacking isn’t just a Chicago problem, with increased incidents reported regionally and nationally.

“There’s something different going on,” Brown said.

Chief of Detectives Brendan Deenihan noted the lack of fear on the part of the carjackers, pointing to one involving a 12-year-old that occurred on Jan. 15, which a woman was parking her car in a garage.

“She came back out and a 12-year-old was getting in her car with a gun,” Deenihan said. “The boy said: `Move or I will shoot you,’ before taking off with her car, prompting a police chase and his eventual arrest.

“This shows the brazenness of these carjackers,” Deenihan said. “And it shows what we’re up against.”