MONTEGO BAY, Jamaica’s tourist capital, is also a hub for call centres. Many work for American companies. But they have less respectable step-siblings: people who scam gullible Americans and brawl with each other over the proceeds. The worlds of scamming and tourism collided on January 18th, when the government declared a state of emergency in St James, the parish whose capital is Montego Bay.

Its murder rate is three times Jamaica’s and 50 times that of New York City. Last year 335 people died violently in a district with a population of 185,000. Britain and Canada have told tourists to limit their movements outside gated resorts.

One cause of the mayhem is scams in which callers, using skills honed at St James’s call centres and contact lists purloined from them, ring up mainly elderly Americans to tell them they’ve won a lottery. The prize is fictitious; the fees paid by the victim to claim it are not.

The scam has lower barriers to entry than the business of shipping Colombian cocaine to the United States, another thriving activity in Jamaica. Weapons for both come from the exchange of drugs for guns with Haiti. Scammers fight over access to contact lists. Couriers bringing in cash sometimes abscond, provoking revenge killings. Gunmen rob scammers when they pick up loot at remittance agencies.

Some Jamaicans see little wrong with bilking Americans. Adidja “Vybz Kartel” Palmer, known to his fans as the “worl’ boss” of Jamaican music, sang “Dem call it scam, me call it a reparation.” He is serving a life sentence in jail for murder.

The government takes a stern view of the violence that scamming leads to. Under the state of emergency, the police and army can search premises and detain suspects without a warrant. The order suspends habeas corpus and allows courts to hold trials behind closed doors. Parliament can extend it after 14 days by a two-thirds majority. That will require votes from the opposition, but it looks as if the government can count on those. The emergency is popular with residents, even though few think it is a cure for violence.

Its success depends on how well the police and army put it into practice. The omens from the police are worrying. At Christmas they staged a “sick-out” to force the government to raise their pay (they failed). In January a prosecutor charged two officers and other alleged members of a gang with murder, robbery and rape.

The emergency started with the busting of a contraband-fuel racket. But after two days, gunmen killed one man and injured five at a gangland funeral. Few tourists will be tempted to explore St James just now.