The Brazilian police said Tuesday that they had arrested an Italian mob boss who had been on the run for 30 years and was convicted of killing more than 20 people in the 1980s. The suspect, Pasquale Scotti, 56, was arrested in Recife in an operation involving Brazil’s federal police and Interpol, according to a police statement. Mr. Scotti was convicted in absentia by an Italian court in 1991 of the illegal possession of firearms, extortion and more than 20 killings. As boss of the Camorra, a criminal group in Naples, he was arrested in a shootout in 1983 in which he was wounded. But in late 1984, he escaped from a hospital where he was being treated. On Tuesday, the police said that Mr. Scotti had been using a false identity in Brazil and that Interpol had identified him through archived fingerprints. Italy has begun the process of extraditing him, the police said. Mr. Scotti has two Brazilian children and was arrested as he took them to school, the Globo G1 news website reported.