ROME — Italian prosecutors are investigating Valter Lavitola on suspicion of masterminding a bomb attack at the home of investigative reporter Sigfrido Ranucci near Rome last October. Lavitola is also under investigation on suspicion of attempting to cause mass murder.

Police arrested four individuals last week on suspicion of carrying out the attack. Authorities allege the four were commissioned by Lavitola. A rudimentary but powerful bomb was detonated outside Ranucci's home in a town near Rome. The explosion severely damaged a car belonging to Ranucci and another owned by his daughter. No injuries were reported. The blast occurred shortly after Ranucci returned home at night. Investigators have not yet established a motive for the attack.

Lavitola is alleged to have instructed someone to identify individuals to plant the bomb and to have paid several thousand euros to those involved. Ranucci, host of "Report," an investigative program on state broadcaster Rai, has been under police protection for years due to threats made against him. Bullets were found outside Ranucci's home in 2024.

Ranucci described Lavitola as "a true friend" with whom he had almost daily contact. Their friendship began in 2019 after Ranucci conducted a journalistic investigation into Lavitola. Lavitola owns a restaurant in Rome where Ranucci is a regular patron.

The last contact between Ranucci and Lavitola occurred when police were searching Ranucci's home. During this interaction, Lavitola was agitated, according to Ranucci. "I am very surprised by this turn of events in the investigation," Ranucci said.

Ranucci also characterized the bomb attack as "a worrying new level" because it transpired "right in front of my home." He has previously written a book about the Italian mafia. In 2021, Ranucci stated that a former prisoner informed him that mobsters "had given the order to kill" him after the book was released, but that the hit "was stopped."