An autopsy was done. IIRC, they're waiting on toxicology results, and the SBI is involved, also. Hopefully, things were done along the way to preserve any potential evidence, such as gun powder residue.
And although this looks very hinky in regard to the married bf, you never know. She had an allegedly abusive husband from whom she was separated.
If you think about it, if you were having an affair, it would be secret, but you might be really worried about your lover if s/he became suddenly incommunicado. Maybe the bf didn't have a key and he waited to report it, hoping she would turn up and he wouldn't have to compromise his privacy by calling the police. And what if she despised her ex and was head over heels with the married bf? It's possible (maybe even likely!) she would redo her will/beneficiaries.
Who knows what went on here? It's pretty hinky that the married bf brought up his "inheritance" to LE and that his wife allegedly thinks he tried to poison her. But, keeping an open mind, it's possible he's telling the truth. The wife could be spiteful or it could be true. And we have seen many "abusive ex-husbands" kill their spouses.
This is an interesting case though, and sad any way you look at.