"It's not that you try not to be scared. Being scared is human," Rio de Janeiro police officer Sávio Resende told VICE News. "But you try not to panic because when you panic you make mistakes, and they could be fatal."
Resende was speaking over the phone from his heavily fortified unit in the vertiginous favela of Morro da Providência — one of the city's Police Pacification Units, or UPPs. The authorities have built 38 such UPPs since 2008 as part of a program to reclaim the city's most dangerous neighborhoods from drug gangs, known locally as traficantes.
"You're in a state of alert all the time, with a million thoughts running through your mind," the officer said. "There's a huge psychological burden."
A recent internal police survey suggests that the burden is becoming too much for many officers as they deal with both the dangers of the job, and the regular criticism they receive for brutality and excessive use of force. An Amnesty International report released in August blamed Rio police for 1,500 murders in the last five years — 16 percent of the total number of homicides in the city.
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The police survey, reported in the newspaper O Globo, found that 29% of officers in the Brasilia UPP in the Complexo do Alemão conglomeration of favelas are suffering from important anxiety-related problems. Their symptoms included feeling nervous, tense and worried, as well as difficulty sleeping and performing their daily tasks "in a satisfactory manner."
O Globo reported that Rio de Janeiro police senior command believe that the proportion of police officers suffering from mental stress is probably similar in all such high risk areas.
Lieutenant Colonel Fernando Derenusson, a senior psychologist at the Rio de Janeiro Military Police Psychological Center, told VICE News that the scale of the problem is related to the fact that officers are now stationed full time in dangerous areas.
"In the past, police activity in dangerous areas would be limited to operations that went in and out [of the favelas]," he said. "Now, officers spend the entire day in potentially hostile situations knowing they could be shot at any time."
According to Derenusson the pressure also continues once an officer's shift is over.
"Often they can't identify themselves as police where they live because the traficantes can force them out of their homes," he said. "More police are killed off duty than when they're in uniform."
According to the daily Folha de São Paulo, 43 police officers were killed in the city in the first six months of this year, while 108 were injured by gunfire.
And some of the deaths are barbaric.
In September, 30-year-old policeman Bruno Rodrigues Pereira was shot, tied up, and dragged through the streets of the Dom Bosco favela until he died. Last month another officer, Neandro Martins, was kidnapped and then burned alive in the Chapadão complex of favelas.
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Derenusson adds that officers are also impacted by their bad image.
"The criticism really affects officers," he said. "They say that they do a thousand good things that no one sees, then one bad thing happens and everybody sees it."
The problem however, is that those "bad things" include a string of high profile cases of brutality and excessive use of force.
The latest incident took place last weekend when five young men aged between 16 and 25 were killed by police when their car was sprayed with bullets in the Lagartixa community in the north of Rio. Witnesses said officers attempted to alter the crime scene, placing weapons in the trunk of the car. Four policemen have since been arrested.
Last April, 10-year-old Eduardo de Jesus Ferreirawas was shot and killed by police in Complexo do Alemão. His mother, Terezinha Maria de Jesus, claimed a policeman standing over the child's body told her "I might as well kill you, just as I killed your son, because I killed a bandit's son."
In another incident, in March 2014, the body of 38-year-old hospital worker and mother of four, Claudia Silva Ferreira, was filmed falling out of the trunk of a police car in the north of Rio and being dragged for 250 meters down a busy street. She had been shot by a stray bullet during a shootout between police and traficantes a few hours earlier. She was dead by the time she reached the hospital.
According to a report by Brazil's Institute of Public Security, cited in the Folha de São Paulo newspaper, there is a death by stray bullet every two days in Rio.
Vanderlei Ribeiro — who runs a support group for police officers and their families in Rio — said media attention to such cases only adds to the problems.
"When a bandido dies, it's all over the media, and there are protests. But when a policeman dies, who cares?," he told VICE News. "They see their colleagues dying, and they think that they'll be next. And they're armed. If they're not mentally balanced, they're vulnerable, and liable to any kind of weakness."
Ribeiro further charged that there is a chronic lack of monitoring within the force to head of the such problems, and pointed to the recent closure of the psychiatric department of the special hospital for military police in Rio. "The police are completely abandoned and left to fend for themselves," he said.
Police Psychologist Derenusson, however, insisted that the organization can meet demand. "The doors of our psychological evaluation service are open to any officer," he said. "We understand the risks, both for the officers themselves and for the public. If we see they aren't in a fit state to work, they can be suspended.
Meanwhile, officer Resende, bunkered down in his favela UPP, doubts that the pressures are going to lessen any time soon.
"It's an extremely violent situation," he told VICE News. "There is no such thing as a pacified favela, there are only favelas in the process of pacification."
Follow James Amour Young on Twitter: @seeadarkness