The Vomero attack, a speleologist's explanation: "Whoever committed the attack knew the sewer system well."

According to technical investigations, the group behind the Vomero robbery used tunnels connected to the city's sewer system. The underground route, dug several meters deep, required specific skills and in-depth knowledge of the area.

The tunnel system under the city

The robbery at the Crédit Agricole branch in Piazza Medaglie d'Oro, Naples, was apparently planned well in advance. According to initial investigative reports, the group that carried out the attack may have consisted of more than six people.

To access the interior of the bank, a complex network of underground tunnels would have been used: passages connected to the sewer system, a further tunnel with access to the sewer through a breach located about one meter above ground, and a vertical shaft approximately five meters high that led directly to the floor of the bank.

During the inspections carried out by law enforcement, together with speleologists, an electric generator used to power the equipment required for the excavation was also identified.

The analysis of the Municipality's speleologist

The speleologist from the Municipality of Naples, Gianluca Minin, explained the complexity of the underground route after the initial technical checks.

According to Minin, the route would have been dug adjacent to the city's sewer system, at a depth of between four and four and a half meters. This underground infrastructure, following the network of main and secondary roads, forms a sort of "parallel city" beneath the urban area.

"It's impossible to chase the bandits through these tunnels, because after the first bend you'll lose them. Even if they had the police on their tail, it would have been impossible to catch them. Because they've learned the route. During my reconnaissance, I found about a dozen forks in the road, and then where you go left and right. Do you understand what we're talking about?"

"The sewer system," he explained, "is extremely complex. Navigating these environments requires appropriate equipment, navigation skills, and experience in managing challenging environmental conditions, such as the risk of flooding during heavy rains."

A difficult path to control

Precisely because of the complexity of the underground network, tracking down any perpetrators through those tunnels would be extremely difficult. According to the speleologist, whoever committed the crime demonstrated a thorough understanding of the system.

"Walking through the tunnels," he added, "it's possible to depart from considerable distances. It's not out of the question that the group could have moved from a point up to two kilometers from the scene of the attack."

Precedents in the city underground

Minin also recalled having encountered similar situations in the past during other inspections in the city's underground.

In a previous case, he said, a makeshift shelter was identified and used as a logistical base: inside were work equipment, spare clothes, shoes, and water supplies, materials that would have allowed the perpetrators to move around and operate in the tunnels for several hours.