Currently, around 1500 people have been detained for the weekend riot, and many remain in police custody. Authorities have five days to charge them.
The map was called “Beach Trip” and was blasted out to more than 18,000 members of a public Telegram channel called, in Portuguese, “Hunting and Fishing.”
But instead of outdoor recreation tips, the 43 pins spread across the map of Brazil pointed to cities where bus transportation to the capital could be found for what promoters promised would be a huge “party” on 8 January.
The post was one of several thinly coded messages circulating on social media ahead of Sunday's violent attack on the capital by supporters of former President Jair Bolsonaro looking to restore the far-right leader to power.
It’s also now a potentially vital lead in a fledgling criminal investigation about how the rampage was organised and how officials missed clues to a conspiracy that, like the 6 January attack on the US Capitol two years ago, appears to have been organised and carried out in plain view.
And like the attack in the US, the Brazilian riots demonstrate how social media makes it easier than ever for anti-democratic groups to recruit followers and transform online rhetoric into offline action.
For more watch Euronews' report in the video above.