By Crispian Balmer
ROME (Reuters) - One migrant is reviled, suspected of killing an elderly couple in Sicily; another has been hailed as a hero, killed after trying to prevent an armed robbery at a supermarket in Naples.
The twin tragedies have shaken Italy, struggling in the face of a massive influx of migrants, and touched off a fierce political debate, with opposition parties accusing the government of doing too little to protect ordinary people.
Police on Saturday arrested an 18-year-old from Ivory Coast after discovering he had a mobile phone, laptop and video camera as he returned to the migrant reception center where he had been living since arriving in Sicily by boat in June.
Shortly afterwards police found the real owners of the gadgets -- both were dead. Vincenzo Solano, 68, had had his throat cut in his apartment, while his 70-year-old wife, Mercedes, had been killed by a apparent fall from her balcony.
The Ivory Coast man, whose name and photograph were splashed across the Italian media, said he found the goods under a tree. Police are analyzing blood on his clothing.
He has yet to be charged, but that did not stop increasingly popular anti-immigration politicians from leaping on the case, saying it showed the migration crisis was out of control and urging much stricter controls on newcomers.
"An elderly couple massacred in Catania, a 'refugee' detained. Which war did this guy escape from?" Matteo Salvini, head of the Northern League party, wrote on Facebook. He added that the migrant center that housed him should be shuttered.
"The INVASION must be stopped at all costs. (Prime Minister Matteo) Renzi and (Interior Minister Angelino) Alfano, how many deaths do you have on your consciences?" he wrote.
Outraged government supporters hit back, accusing their detractors of playing dirty games for cheap political gains.
They also pointed to the death on Saturday of Anatoliy Korol, a 38-year-old Ukrainian migrant, who was shot dead in the southern city of Naples after he tried to defend staff facing masked gunmen in a supermarket hold-up.
Korol had been in Italy for 10 years, and had a job and a family. He died in front of his daughter. He was swiftly held up as an example of the positive face of immigration and praised by the regional governor in Naples as a "martyr of justice".
Stefano Esposito, a senator from Renzi's Democratic Party, said Salvini's comments on the Sicilian case were "unworthy".
He added: "If we really have to reply to you, how do you explain the Ukrainian builder, killed two days ago during a robbery while trying to halt criminals, who were possibly Italian?"
More than 111,000 migrants and refugees have reached Italy's shores so far this year, overwhelming local reception centers and forcing the government to seek help from European Union partners.
Far-right parties have urged a more muscular approach and their fiery rhetoric has won them backing. The Northern League, though only rooted in the north, is now Italy's third largest party, with support put at 15 percent, up from 6 percent a year ago.
(Editing by Mark Trevelyan)