Ciudad Juarez is one of the world's deadliest places
Mexican soldiers have arrested a man in connection with the killing of two Americans and a Mexican in the border city of Ciudad Juarez, officials say.
Local reports suggest the suspect is a leading member of a local drugs gang.
A US consulate worker, her husband and a Mexican national were killed as they were leaving a birthday party in Ciudad Juarez earlier this month.
More than 2,500 people died last year in Ciudad Juarez, one of the focal points of Mexico's illegal drugs trade.
Lesley Enriquez - a US citizen working at the Juarez consulate - her American husband, Arthur Redelfs, and Jorge Alberto Salcido, the Mexican husband of another consular employee, were shot dead in two separate incidents on 13 March.
The motives for the killings remain unclear.
US Secretary of State Hillary Clinton, who was in Mexico as part of a high-level US delegation last week, pledged increased support for Mexico in the fight against drug gangs.
She said more would be done to cut US demand for drugs and the flow of profits and guns into Mexico.