A 74-year-old Italian pensioner shot dead two neighbours and then his wife before turning the gun on himself.
Jealousy over his wife's infidelity appeared to be behind the rampage in the northern city of Genoa, police said last night.
Carlo Trabona, a retired bricklayer, first went to a coffee bar where he shot one of his neighbours. As the other one ran away, Trabona followed him, shot him and then went back home where he killed his wife, according to police.
After police surrounded his building, Trabona shot himself, said Alfredo Federici of the Genoa police. The two neighbours, who were brothers, and the gunman died later in hospital, he said.
Mr Federici said an alleged infidelity may have triggered the shooting spree, as Trabona suspected that his 72-year-old wife had been having an affair with one of the neighbours, who were also his friends.
Reports also said the gunman had a history of mental problems.