To me, the hate crime theory seems more plausible. If they were trying to get at the translator (which seems ridiculous to begin with), then they would not kill the cousins.
The cops are onto something here. BTW, what's your real name and address? Some people might want to talk to you about why you jumped into this particular thread so quickly with a transparant attempt to discredit the police investigative theory.
If you call the local FBI office, they'll have an investigator in charge all evening, so if you have some information to impart to them, you might give them a call.
First, murder is itself a ridiculous act, so what seems ridiculous to you is irrelevant.
Second, to assume that the purpose was to get to the interpreter is a leap on your part. The father of this family was open and up front about his heritage and views and had drawn the ire of the jihadis. If they were related to someone the jihadis might already be watching it only makes more likely that they could be found by the bad guys.
You're making a causality connection that may obscure a more relevant relationship.
How similar is the names of the cousin? Could it be mistaken identity.....(Off with tinfoil)
This was a message from the terrorists to the ENTIRE Coptic Christian( and ALL Christians, for that matter)... They WILL KILL ANYBODY THEY FEEL LIKE KILLING!! ANYBODY!