Strange little red berry or fruit

[Dcreelman1982]

Hello, I'm new here and well I have a question and this seems a good place to start. I'm from Rhode Island and today my 16 month old son decided it would be a great idea to eat a little red berry of some sort and I'm just trying to figure out what it is. There are no others around, so I'm assuming that and animal had brought it into my yard. I will attach some pictures. I should also say that it's hard and it has a sour taste to it, but smells fruity.

Thanks,
Derek

 

[Chuck]

Looks a lot like a choke cherry,bitter but not poisonous. Not positive though