There could be additional reasons for the fall off in murders:
1. They’re running out of rival gangbanger narcos to kill.
2. One gang has won.
3. The police have all but surrendered to the lure of plomo or plata.
4. Non reporting of bodies found out at the dumping ground anymore. Just report the killings in the center of town or on streets near churches and schools.
“There could be additional reasons for the fall off in murders”
Yes, a lot of the drug trade is now being conducted in Central America like Guatemala which has the highest murder rate in the region
“One gang has won”
My understanding is that you’re right on this one, and the Sinaloa cartel effectively has beat out the Juarez cartel for control over the region
“The police have all but surrendered”
My understanding is that law enforcement — local, federal and military — has helped in reducing the violence, and this is one reason why more Mexican drug cartel activity is being conducted south of its border in Central America.