I'm very sorry to hear about the murder.
As for the "incense." I have a bit more on it here (cf. here, but link rotted). Mainstream views seem to be that the material is either just dirt or a local cleaning agent, and its status is, at best, unconfirmed.
The article reports that the Qumran Project is planning to conduct scientific tests on the surviving residue of the material. Given that, reportedly, much of is floor sweepings, I imagine modern contamination could be a concern. But let's see what they find.
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