The four people found dead on the Mexico-Toluca highway, near La Marquesa, were alleged robbers who minutes before their death tried to rob a passenger bus heading to Mexico City.
According to the statement given by witnesses, the bus departed from San Mateo Atenco and the four alleged robbers boarded the bus in San Pedro Tultepec.
Minutes later, the four people threatened passengers with a gun to steal their belongings and when the suspects were leaving the bus, one of the passengers pulled out a gun and shot them to death.
After the shooting, the bus continued on its way towards Mexico City and the unidentified shooter left the bus a few stops later.