H E IS ONLY ten minutes late, which by the norms of Brazil’s capital amounts to being early. Yet Sérgio Moro apologises profusely, explaining that he was called to a meeting with congressmen. The politeness and an occasional boyish smile are trademarks he deployed as Brazil’s most media-adept judge. They should not be misread. There is a quiet steeliness to Mr Moro, who locked up a string of political and business heavyweights for corruption, including Luiz Inácio Lula da Silva, a still-popular former president.

Having thus helped to prevent Lula from being a candidate in last year’s presidential election, Mr Moro controversially went on to accept a job from its winner, Jair Bolsonaro, a firebrand who admires military dictators. He heads a beefed-up justice ministry, in charge also of public security, the federal police and an anti-money-laundering agency previously lodged in the finance ministry. His mission is to get the federal government to apply the same zeal as he did in his courtroom to the fight against corruption and organised and violent crime. It is a popular cause. But there are risks, both for his reputation and for Brazil.

Mr Bolsonaro’s government has got off to a slow start, with much internal bickering. On February 13th the president left hospital after an 18-day stay to deal with the effects of a knife attack he suffered during the campaign. But Mr Moro has been quick off the mark. On February 4th he unveiled an anti-crime bill. This would impose tougher sentences for murder, armed robbery and corruption, and for association with several named criminal gangs. It would make illicit campaign donations a crime. And it would make it easier for police who kill to claim that they acted in self-defence.

Police often have to face heavily armed criminals. But critics say they are too trigger-happy against young black men, and that Mr Moro’s proposal is a licence to kill. Mr Bolsonaro has advocated giving police just that. Mr Moro rejects “categorically” the accusation that he is giving police permission to murder. His proposals “are not discordant with what happens in other countries”, he says.

Much of Mr Moro’s bill makes sense, as far as it goes. Brazilians voted for Mr Bolsonaro partly out of horror at the spread of violent crime. This is now affecting politics. In several places the old political machines have been taken over by organised crime, says Matias Spektor, an academic. Previous governments downplayed the power of criminal organisations, says Mr Moro. The state is now “acknowledging them, and will act with rigour”.

Mr Moro’s biggest tests lie beyond his bill. Reducing crime involves more than tighter laws. It needs better policing and community work in the favelas. Much of this is the job of state governors but requires co-ordination from the top. The minister says Mr Bolsonaro will do that. But it is hard to see the president being interested in such wonkery. He has already issued a decree liberalising gun ownership, against the advice of Mr Moro. Human-rights groups report an increase in hate crimes against women and gay people, whom Mr Bolsonaro has often publicly denigrated.

One of Mr Bolsonaro’s sons, Flávio, a newly elected senator, is raising suspicious eyebrows. Investigators in Rio de Janeiro have found that $1.9m passed through the account of his driver, and that Flávio, when a state legislator, employed relatives of a fugitive former police officer accused of leading a paramilitary militia (Flávio denies wrongdoing). Mr Moro says that the police and prosecutors have complete freedom to investigate this case.

For some Brazilians, Mr Moro will be forever damned for having seemed to act at the edge of the law in his pursuit of Lula. To many others he is a hero. He insists that his mission is to apply the rule of law. “It’s important that he stays, because he’s a moral figure,” says Thiago Vidal, a political consultant in Brasília. But Mr Vidal, like many, thinks that Mr Moro is eyeing a vacancy at the supreme court which will crop up next year (he neither confirms nor denies that).

Mr Moro is a celebrity in a cabinet long on military men and inexperienced or barely rational civilians. As with Paulo Guedes, the market-pleasing economy minister, Mr Bolsonaro needs Mr Moro more than the minister needs his boss. That gives him the clout to restrain a president whose past career and statements show little devotion to the rule of law. “Any government should be judged by its actions,” insists Mr Moro. That now includes him, too.