In gritty cities like Ciudad Juárez, these domes now appear wherever the trappings of upward mobility are for sale, mainly at upscale malls and housing developments.

In fact, while Islamic touches have often signified wealth in Mexico, some academics who study the culture of Mexican crime say the domes, or cupolas, have become visual shorthand for the drug trade’s enduring appeal: it offers a way to move up. For many people here, crime represents a meritocracy in a country of oligarchy and poverty. Work hard, do what it takes and a crime boss will reward you with money, cars and responsibility.

“They find in the narco world everything they cannot find anywhere else,” said José Manuel Valenzuela, a sociology professor at El Colegio de la Frontera Norte, a research institute in Tijuana. “It’s not just about money. It’s about power.”

Showing off that power made more sense in the early years of the drug boom. In the ’70s and ’80s, even into the ’90s, building like a king impressed recruits and competitors. But over time, as conflicts have increased among the cartels, and as the Mexican and American governments have tried harder to crack down on trafficking, drug lords have been keeping a lower profile, buying existing houses rather than building obvious, ostentatious houses from scratch.

Indeed, most of the homes I visited were hardly palaces. Many were entirely average and darkly utilitarian, including a beige concrete home in Juárez known as the House of Death because of the dozen bodies found there in 2004.

Even on the more luxurious end of the spectrum, most of the homes could best be described as upper-middle-class. Packed into nice neighborhoods, they were usually three- to five-bedroom houses of around 3,000 square feet, lacking exterior charm or adornment. The biggest tipoffs about the occupants: a shortage of street-facing windows, and the best security systems money could buy.

MIX AND MATCH (BUT MOSTLY JUST MIX)

Imagine entering a furniture store and being told you had 60 seconds to choose the furnishings for 15 rooms. Most of us would freeze. But the houses of some capos suggest that they made snap decisions. As in, “Give me one of everything.”