This is an American news story. Here, Asian means Oriental, which is where ninjas, samurai and kung-fu monks come from. But we shouldn't say Oriental any more because it reinforces racist notions about which direction the Roman Empire thought the sun rose from in the morning. (Part of that is a joke, but, sadly, not enough.)
If it was a European news story, Asian would mean Muslim and nothing more, though you can usually make a good guess based on the country: English Asians are mostly Pakistani, German Asians are mostly Turkish, French Asians are mostly Tunisian, Algerian, Moroccan, etc, Italian Asians are mostly "Syrian, *wink* *wink*", and so on.