Although the sudden intensification of these power tool capers has bedeviled law enforcement, criminologists point to several converging factors.

“You need a few ingredients to create a crime wave, and one is opportunity, and one is incentive,” said Stanford University law Professor George Fisher. Incentives — namely, need and desire — don’t change over time, he said, but opportunities and circumstances shift.

Fisher wondered, additionally, whether precautionary measures like locks and kill switches have made thieves more confrontational, using firearms to demand items they can’t easily snatch from a locked vehicle.