Experts said the arrest was a sign that the administration of President Felipe Calderón had refocused its efforts against the criminal group, but Eric L. Olson, a senior associate at the Mexico Institute of the Woodrow Wilson International Center for Scholars, said that by itself, the arrest should not be seen as a triumph.
“It is now more important than ever for the government of Mexico to demonstrate that it can go beyond the capture of cartel leaders and turn the captures into prosecutions and ultimately the dismantlement of the entire criminal network,” Mr. Olson said. “Good law enforcement should include effective prosecutions.”
Several years into Mr. Calderón’s declared war on the drug gangs, successful prosecutions are still rare, and corruption among public officials is still rampant. Mr. Rejón, the authorities said, was arrested just outside Mexico City, along with a municipal police officer hired to arrange safe passage to Mr. Rejón’s mother’s house in Campeche.
Mr. Rejón has been among the most sought of Mexico’s criminals for years. A former special forces soldier, he has been accused of several murders, of drug trafficking and of trying in 2004 to help a patron break out of prison.
The federal police said that more recently, he was the Zetas’ boss in central Mexico, including San Luis Potosí, the state where Jaime Zapata, an agent with United States Immigration and Customs EnforcementImmigration, was shot and killed in February.
Mr. Rejón was in the state coordinating Zetas activity at the time, according to the Mexican authorities, but his exact role in Mr. Zapata’s death is unclear. Mr. Rejón was also being investigated for the deaths of dozens of migrants found in unmarked graves this spring and summer.