Caught in a TABC Sting

[MDTEXAS]

My question involves criminal law for the state of: Texas

I was caught in a TABC sting here in Texas. My only defense is that I asked her if she was twenty one years of age. (I was under the impression that the decoys could not lie.) She said yes. I rang up the order. Then my brains kicked in. I had to ask twice and she smiled strangely. I stopped her before she left the store, asked to see her id, and found she was 20 and eleven months old. I took the beer away from her, and as I was heading back for the counter the TABC agents took the beer from me and off I went to jail.
So my question is when is a sale considered complete?

[flyingron]

Technically, it was complete as soon as you accepted her money and she had possession of the beer. Yes they are allowed to SAY they are old enough. That's why you're supposed to ask for the ID first. You might get a sympathetic hearing that you caught her before she left.