Okay, I have kind of been following this case. I think one of the articles said that the owner of the home had not met the occupants and all of the dealings were done through a realtor. If this is the case, wouldn't you think that a realtor would qualify the renters to ensure that they had the money to rent? I haven't rented in a while; so, perhaps, the $3,000 security deposit was good enough to get them into the home.
The family was getting the money from somewhere. This kind of money was not likely saved from the low paying jobs that the two adults had.
It does seem that the entire family slaughter was meant to send a message to someone. Perhaps, the father was in the gang and selling drugs until he could get enough money to start over somewhere with his family. The gang killed him for trying to get out. You know, sort of like the Sopranos...they don't just let you out of the "family." You are in for life and have to keep selling/working for them or you will get killed because you know all of the "family" secrets.
Or, could the father have been a government informant? This seems less likely because you think that he would have been protected.
Last guess: Perhaps, the gang was sending a message to his brother. Maybe, the brother didn't really escape from prison. Maybe, he became an informant for the government. So, this was actually a message to him saying, "Hey, we know what you are up to; and we will kill all of your family until we find you."
ETA: One more idea: Could the escaped brother (Jose Manuel) have been feeding info to the Feds via the murdered brother (Jose Luis)? This would account for Jose Luis being on the cell phone at various hours outside of his home. Jose Manuel could have been receiving money and sent it to his brother to use or the Feds could have been paying Jose Luis directly for the info.
Just brainstorming here.
