The Candelária Church is a historic Roman Catholic church in central Rio de Janeiro, Brazil. By the early 1990s the church and the surrounding buildings in Pius X Square had become a nighttime refuge for large numbers of the city's street children, to whom church personnel offered food, shelter, education and religious guidance. Many of the children were connected to the drug trade and to prostitution, and as pickpocketing and robbery rose in the area, police kept a constant watch on the church's surroundings.
On the night of 22–23 July 1993, several Chevrolet Chevette cars with covered license plates stopped in front of the Candelária Church, and their occupants opened fire on a group of roughly seventy street children sleeping nearby. Eight people were killed, six of them minors; the youngest, Paulo Roberto de Oliveira, was eleven. Survivors said that on the morning before the attack a group of children had thrown stones at police cars. Investigators later concluded that the shots were fired by militiamen who used the square as a point for selling drugs, and several other people were wounded.
The inquiry led investigators to Wagner dos Santos, a teenager who survived despite being hit four times. His identification of those involved was central to the case. He was attacked again on 12 September 1994 at Central do Brasil and was subsequently placed in the state's Witness Protection Program before leaving the country with federal assistance; he continued to suffer serious health problems.
Seven men were indicted, among them a former military police officer, two serving military policemen and a locksmith. Three defendants were acquitted, and one was not tried for the mass killing but received a two-year sentence for possessing one of the weapons used. Three men received convictions following extended appeals: Marcus Vinícius Emmanuel Borges was ultimately sentenced to 300 years in a February 2003 trial; Nelson Oliveira dos Santos, initially absolved despite a confession, was convicted on the prosecution's appeal in 2000; and Marco Aurélio Dias de Alcântara was sentenced to 204 years. The source records that the convicted men nonetheless remained free through pardon or parole.
Studies linked to Amnesty International reported that forty-four of the seventy children who had slept in the area later died violently, and that most of the young victims were poor and Black. By the 2023 thirtieth anniversary, most survivors had died or gone missing, among them Sandro Barbosa do Nascimento and Elizabeth Cristina de Oliveira Maia, both killed in 2000. A wooden cross bearing the victims' names stands across from the church; for the anniversary, the Rio de Janeiro City Hall renovated the memorial.