From the web site wildedibletexas
"When agarita berries are ripe, they can be plucked from the bush and eaten raw though the tender-fingered should beware."

Actually, I had seen red berries in an agarita bush, I started plucking them, and ate a handful quickly as I have done in past years.  I was thinking to myself, these don't taste like I remember.  Then I discovered there was another plant growing amongst the agarita.   After a quick search on the web, I found out Nandina berries, while toxic to birds and other, are considered non-toxic to man.  

"The berries of the nandina plant contain hydrocyanic acid and are poisonous. They are toxic to cats, dogs and other grazing animals, and they can cause animals to experience seizures, comas, respiratory failure and death. They are considered nontoxic to humans but may cause stomach pain if ingested."

Thankfully, I lived! Moral: the stupid,  in addition to the tender-fingered, should also beware!