President Gustavo Petro ordered an investigation into the attack on Miguel Uribe Turbay, which authorities said was carried out by a minor under 15 years old.
Colombian Sen. Miguel Uribe Turbay was shot in the head during a campaign event in the capital, Bogotá, on June 7.
A presidential hopeful, Uribe, 39, underwent an initial operation for his injuries, and remains in serious condition on June 8.