A police officer has been murdered in Rocinha, a Rio de Janeiro favela occupied by police since last year, as part of a wave of violence that seems to have been caused by security forces disrupting established criminal networks.

Rodrigo Alves Cavalcante was killed early Wednesday morning while on patrol in Rocinha. Police have identified the suspect, an alleged drug trafficker who they say shot Cavalcante after he asked him to stop for questioning. Cavalcante is the first police officer to be killed in a “pacified” favela, reports O Globo.

Some 150 special operations police (BOPE) have been sent to Rocinha following the killing, reports the AP.

The neighborhood was already held by the authorities, after some 3,000 military police “invaded” it in a pre-dawn raid in November last year, in part of the city’s drive to seize control of selected shanty towns from the drug traffickers and militia groups who have long controlled them.

However, despite the apparent initial success of the operation to pacify Rocinha, violence has hit the neighborhood this year, with nine people shot dead there since February, according to the AP. Three people died in a shootout in March, which was thought to be a clash between members of the Amigos dos Amigos drug gang. The group dominated Rocinha until the police occupation, when gang boss Antonio Francisco Bonfim Lopes, known as “Nem,” was arrested while trying to flee in the trunk of a car.

Days later, a community leader who had been due to testify in the case against Nem was shot dead in broad daylight outside his community center in Rocinha. He had been accused of being part of the Amigos gang.

InSight Crime Analysis

Rio Radar, in a piece written before the latest murder, claimed that the wave of violence may be due to a rival gang taking advantage of the power vacuum created by Nem’s arrest.

The website argues that the police invasion disrupted established power dynamics, dislodging Amigos dos Amigos, who had controlled the area since 2006. This stability, with a single criminal group in control, had meant that the area saw less shoot-outs and overt violence than some other favelas. Sources told Rio Radar that the Comando Vermelho gang had taken the upper half of Rocinha, while Amigos continued to hold the lower part. Some reports say that the Comando Vermelho ordered the shooting of the community leader.

This pattern mirrors that seen in places across Mexico, where government action to dislodge the dominant criminal group is often followed by an outbreak of violence, as other gangs fight to gain control of the newly-available territory. The city of Medellin, Colombia, offers another example of the phenomenon, with the supposedly reformed city seeing a fresh hike in the murder rate after criminal boss Diego Fernando Murillo, alias “Don Berna,” was extradited to the US in 2008.

In Rio, the military police denied that the killing was a sign of the failure of the Rocinha occupation, and said that the main gang bosses had been arrested, and police had brought about an “absolute disarticulation” of their criminal structures.

With the latest murder, it seems likely that it will be some time before Rocinha is peaceful enough for the installation of UPP forces. But Rio authorities will no doubt pour resources into the area, which is a crucial site for them to control. As a former police captain told the Associated Press in November, the neighborhood has high strategic importance, and its pacification will allow the police to close a security loop around the parts of the city which will host most of the World Cup and Olympic events.

See video report, below.

A version of this article was published on the Pan-American Post.