What is the extent of Charity scams?

Hello and Salutes,

I am an amateur writer. I'm developing a story wherein some people are involved in a charity scam. That is, they are the owners and proprietors of a small charity firm and use this for fraudulent tax evasion and such personal agenda.... against the law.

Now they happen to become the new neighbors of a wealthy yet lonely elderly woman. Now the scammers try to acquire her property through fraud. First they befriend her. Then they make her oblige to donating her huge real-estate for the charity, but after her death.

The scammers' idea is to have her murdered after she signs the papers, and acquire the real-estate donated to the charity firm and turn it into their personal property.

I am not sure if the above plot is technically correct. Should it be possible to acquire the real-estate donation as said above, and turn it into personal property through fraud, in the setting of a charitable firm?

Many thanks.

(English is my second language, and sorry, if some of my choice of words is not correct).

Oh I forgot to add... I'm not writing a novel. It is just a short story, of about 5000 words, max. Therefore I don't need any elaborate reply, I just want mention of the possibility for fraud as stated in the OP. Nobody wants that many details, as readers of a short story. Thanks.