Mexican authorities arrested a couple believed to have kidnapped, tortured and murdered a seven year-old girl on Wednesday, days after the discovery of the victim's body sparked protests in the violence-wracked country. The suspects "were detained in a town in the State of Mexico," Mexico City mayor Claudia Sheinbaum tweeted, without giving more detail. Prosecutors on Tuesday released pictures of the two suspects -- identified as Giovana and Mario Alberto "N" -- after searching a house near the victim's home.