Migrants Killed in Mexico

1. What's being discussed in this article?
2. When did the event happen? (Is this breaking news or something that's been analyzed and discussed for a while?)
3. What questions do you have that would help make this article make more sense to you? What more do you need to learn about to be able to report on this event?

In this article the dangers of the combination of drug cartels and illegal migrants in Mexico are being discussed. Just two days ago it was reported that Mexican police found the bodies of 72 migrants trying to reach the United States. The migrants were believed to be from different parts of South and Central America. Mexican officials believe the drug cartels have something to do with the deaths of these migrants. They have reported that it is very common for drug cartels to do extreme harm to those who refuse to work for their gang. Additionally, officials say that migrants are a drug cartel's prey seeing that they carry a lot of money with them as they make their journey to the United States.

Where are the members of the drug cartels that committed these crimes?
How strong or weak is Mexico's border security?