Footage released by Montgomery County Police shows a suspect assaulting a woman during an armed carjacking at a Chevy Chase, Md., gas station on Jan. 21. (Video: The Washington Post)

A year of the coronavirus has given rise to what police leaders nationwide call an alarming trend: bored, wayward teenagers pointing guns in people’s faces and carjacking them.

In Chicago, the frequency of the crime more than doubled in 2020 to a rate of about four per day. Three teenagers are charged with murder after a 65-year-old retired firefighter was shot in December during a noontime holdup in a busy shopping district.