What JEBtrois said sums it up for me.  

Its a gruesome tale, and horrible to think about.  Indeed, we were traveling in the same waters as that unfortunate couple just 6 weeks ago (sailing up from Trinidad), so it certainly spooked us a little.  But as they say, s*** happens, and alas these poor sailors were just in the wrong place at the wrong time when escaping prisoners needed a vehicle to flee their country's jurisdiction.  Sort of the marine equivalent of a carjacking. 

In the end, you need to keep in perspective that there are A LOT of sailboats cruising in the Carribean and yet the incidence of things like this appears to be very (and perhaps even surprisingly) low.   One must use common sense (such a securing the dingy against theft, etc.), and follow reports on site such as CSSN ( https://safetyandsecuritynet.org/ ) to avoid certain anchorages with repeated issues.     Just like I wouldn't walk alone on dark streets at 3 a.m.  on certain streets in my home city of New York, or leave my bike unlocked outside a store.   

As to your plans to cruise the Bahamas, although we haven't extensively cruised there as much as others, my sense is that -- outside of parts of Nassau and Freeport, perhaps (which aren't, IMHO, great cruiser destinations anyway) -- the incidence of crimes against boaters is very low.   We certainly felt very safe in the Berry Islands and the Exumas.