After notorious Mexican drug kingpin Joaquín “El Chapo” Guzmán was arrested last year, Mexico had a national spike in homicides linked to the scramble to fill the cartel power vacuum. Officials widely described his capture as a breakthrough in the war on drugs, but according to a report released Friday by the Justice in Mexico Project at the University of San Diego, his arrest precipitated a spike in the national murder rate from 17.5 per 100,000 residents in 2015 to 21.3 murders per 100,000 inhabitants in 2016. El Chapo was arrested in January 2016. The steep incline rivals national homicide record numbers earlier in the decade, the report says. "It's kind of two steps forward, one step back," said David Shirk, a co-author of the report. "We took out a very powerful and important drug trafficker. But as a result, we have destabilized the ecosystem of organized crime in a way that has led to internal struggles within the Sinaloa Cartel, and encroachment from other organizations that would like to take over their business."