Ok, I meant to ask earlier, but when I heard this same phrase for the third or fourth time while watching "¿Quién mató a Sara?" it just really started bugging me: this seems to be a great example of the impersonal ellos form (the whole premise is that he thinks she was killed but doesn't actually know who did it!) but I can't understand why that "la" is there. "La mataron" or "A Sara Mataron" I get, but how isn't it redundant to have both...?
If anyone knows what's going on here, thanks in advance for any insight you're willing to offer! (but no spoilers please!) 😂