Police in Brazi carried out a massive anti-murder operation across every state, arresting 968 suspects in just one day.
Officers shared real-time updates of the so-called Operation Cronos on social media, including photos and videos.
Of the detained, 56 people have been accused of gender-based killings and domestic violence.
Officials said they hoped "to prevent future crimes" by "imprisoning murderers".
During the first phase of the operation in August, police arrested nearly 3,000 people.

US House passes $1 trillion defence bill despite Iran, Israel concerns
US military marks 11th successive night of attacks on Iran
US says it reaches nuclear power deal with Saudi Arabia
Indian opposition disrupts parliament to support student protesters and pressure Modi
Rubio says US still willing to negotiate over Iran crisis
