Giz Explains: How does the electronic anklet?

Giz Explains: How does the electronic anklet?

In addition to the judge Sergio Moro and the winning vigilantism, one of the great stars of the Lava-jet operation is the electronic anklet, the accessory of remote monitoring which now decorate the legs of those involved with the megaesquema corruption at Petrobras.

Since last Saturday (2), for example, Fernando Cavendish, owner of the construction company Delta, and the bookie Carlinhos Cachoeira await their anklets to leave the Penitentiary of Gericinó in Bangu (RJ) – which has not happened for alleged delays payments made by the State Department of Penitentiary Administration (SEAP) the supplier of the equipment.

With so many floodlights, electronic anklet turned the gadget of time in Brazil – and this aroused our curiosity about what concerns the theme. Come on!

The anklets and the law
The story of the origin of anklets is doubtful, but deserves to be told. The most accepted version, including the American media, is that the American Jack Love judge had the idea for the device creation in 1977 to read a story of Spider-Man. In it, the villain Kingpin shall monitor the hero through an electronic bracelet .

Love would have been delighted with the idea of monitoring, and convinced a friend, Mike Goss, to create something. Then came the anklets, which began to be used by the State of New Mexico – know this story here .



With the first law, the idea was to be able to keep an eye on temporary outputs and sentenced to house arrest. The second law aimed to reduce the number of persons awaiting trial in prisons, as 41% of inmates in the country fall into this situation. São Paulo was the first state to monitor its inmates, followed by 18 other states.

Thus, the anklet can be used in the following situations: temporary prisoners (awaiting trial), trapped under house regime and prisoners in semi-open regime. In addition, they can be used for temporary departures of prisoners, as on Christmas reprieve, and protective measures for victims of domestic and family violence, including crimes against women, children, adolescents, the elderly, sick and disabled people.

According to a study of December 2015 the UNDP (United Nations Development Programme) commissioned by the Ministry of Justice, most anklets in the country are destined to open system / semi-open / closed under house arrest (49.55%), the semi-open regime with external work (19.89%), and the temporary output (16.57%).

They are also used in other cases, as many precautionary measures from prison (8.42%), and protective measures such as the Maria da Penha Law (4.21%). To require the use of anklet, defender or lawyer should petition with the competent criminal court or the judge of criminal enforcement.

How it works
In anklets market prevail companies in our own country, often so that common scheme to the Brazilian industry: domestic technology, but with imported components.

Among the names that we find in contact with the Ministry of Justice or the state departments are IC equipment, EU and Brazil Geocontrol – beyond Spacecom, which claims to have 90% of the national market. Among the gringo companies with technology, it is 3M (the same as does the Post It and Scotch Brite sponges).

The absence of imported products takes place because of the price and technical incompatibilities – some of these anklets, for example, operate at frequencies not approved by Anatel.

This is not the only similarity between the accessory and a smartphone. The anklet also uses the GPS system to determine the location and network operators to transmit the data traveling encrypted APN (Access Point Name) itself. If at any time the wireless network is not available, the data is sent later.

In the central, alarms are triggered if the monitored violates the conditions (such as location and hours) that allowed out of jail. From this, the center can make telephone contact, audible contact by the anklet or even send a PM to check the situation.

Thus, the battery consumption looks like a smartphone – you know what happens when it gets to the phone’s GPS on all the time. The autonomy of the anklet is between 19h and 24h with continuous data transmission. Recharging is done by a multi-voltage charger with an extension of up to 3 meters.

It weighs 200 grams and is resistant to dust and water. The devices of Spacecom meet IP68 standard, which enables dip the device for up to 1.5 m for 30 minutes. This allows the monitored bathing and to get into the pool without leaving the radar.


According to the study of UNDP, 18,172 people were monitored for anklets in Brazil until last year. According to Spacecom, a company that provides equipment for several states, the current number is 22 000 anklets activity.

The Department of Penal Execution of Paraná (Depen-PR), the land of Lava-Jato says 3000 people carry the accessory on your legs in the state today. In history, 7800 monitoring have been made in Paraná.

In São Paulo, which has the largest prison population in the country between 6000 and 7000 anklets are in activity. The estimate is the president of the Public Safety Commission of the OAB-SP, Arles Gonçalves Junior.

More importantly, almost no one dares to say what is the size of the demand unmet anklets in Brazil. Gonçalves Junior, however, gives an idea of the size of the problem. “Two years ago, we worked with the Secretariat of Public Security, the PM, the Civil Police, the Federal Public Ministry and the Public Defender ‘s Office and concluded that, to meet only the case of Maria da Penha Law, it would take 20,000 anklets “he says. This only in the state of São Paulo.

The lawyer estimated that in São Paulo, whose prison population exceeds the mark of 200 thousand people, “easily” between 40,000 and 50,000 could use anklets. Why is this not done? Money.

“It should be easy for a company to deliver 20,000 anklets once, and security departments are bankrupt. Not only the anklet. You have to have the infrastructure to do the monitoring. When the alarm is triggered, the PM needs to go to the location, “says Gonçalves Junior. The Rio case cited in the text of the beginning is an example. According to Spacecom, the state debt to the company is $ 2.8 million.

The problem would be the money to invest. Still, the average cost of an anklet is much smaller than the amount spent per inmate in prison. According to Depen-PR, the anklet has cost R $ 241 per month, according to the contract with Spacecom. The value includes monitoring by the company (but the state maintains parallel monitoring).

Spacecom already reported a more expensive average value of your service: R $ 280 per month. And the company says that inflation in 2016 should make this number grow. In Brazilian chains, the average cost per inmate is between R $ 1,800 and R $ 4,000 per month, according to the National Penitentiary Department.

The fact is that even with unmet demand, the segment of anklets is flourishing, going against the crisis. According to the Brazilian Association of Electronic Security Systems Companies Association (Abese), this market grew by 6% in 2015, reaching sales of $ 5.4 billion – and the forecast is for another 5% this year. Only Spacecom grew 296% between 2010 and 2015.

Thus, the anklet is no longer something comic book to turn the smartphone wrapped with Justice. And it must popularize increasingly in the country Lava-Jato. Just missing money.

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Giz Explains: How does the electronic anklet?

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