"Many New Mexico communities will breathe a sigh of relief because fugitive Salas, a child killer, will no longer outrun the justice that is long awaited," Conrad Candelaria, U.S. marshal for New Mexico, said Thursday in a release.
The United States will seek Salas' extradition to New Mexico, Candelaria said.
Salas has been on the Marshals 15 Most Wanted list since December 2011. He escaped from the Curry County Detention Center in Clovis, N.M., in August 2008, and had been on the run ever since, the service said.
When he escaped, Salas was serving a life sentence plus 56 years for his role in the 2005 murder of 10-year-old Carlos Perez.
Noe Torres, also charged in the Perez slaying, was arrested in Mexico earlier this year.
In July, Vincent Legrend Walters was apprehended in Cancun, Mexico, after being on the most wanted list for nearly 24 years.