they prove this gun that mysteriously appeared is also the same gun Alexis was seen tossing? Any good lawyer would argue this gun is a decoy sent to cast doubt while the real gun she used to kill Cates is still in the river. So what if this gun is registered to Sonny? He has a lot of weapons. He could've just pulled one, soaked it in the river for a bit and had someone deliver it to the PD (is what I'd argue as a prosecutor).
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