The Brazilian Senate is set to vote on a measure that would lower the age of criminal responsibility from 18 to 16 years of age.

Critics warn the controversial bill, passed last month by the lower house of Congress, will add to Brazil’s already overcrowded and dangerous adult prisons.

Leading up to the vote, student groups in the Northern city of Macapa staged protests against the proposed legislation.

"The goal is to raise awareness that age reduction is not a solution,” said Amapa;StudentUnionPresidentGabriel Martí.

Overcrowding in Brazilian prisons is partially due to slow judiciary process, as 39 percent of the country’s current prison population is still awaiting sentencing.

Human rights nongovernmental organization Conectas estimates that Brazilian prisons must boost capacity by more than 200,000 spaces to avoid overcrowding.

Brazil has the fourth-largest prison population in the world after the United States, China and Russia. While the inmate population in those countries has decreased in recent years, Brazil’s prison population increased by 33 percent between 2008 and 2014, according to a recent report by the nation's justice ministry.

Under the current sentencing laws, adolescents convicted of a crime in Brazil can only be jailed for three years or until they turn 21, and the crime will not be recorded.