Mexican authorities have arrested a crime leader they say has confessed to ordering or being personally connected to more than 600 murders.
State of Mexico attorney general Alfredo Castillo said 36-year-old Oscar Osvaldo Garcia Montoya leads The Hand With Eyes organisation.
It is a brutal group that operates mainly in and around Mexico City, where at least 300 of the murders are alleged to have taken place.
Mr Castillo said Garcia is a military deserter who became a bodyguard for major drug cartel figures before splitting off to start his own crime organisation to sell drugs on the streets.
The Hand With Eyes is blamed for bringing drug violence to the capital area and is known for decapitating many of its victims.