Calling All Birders - Identify This North Texas Hawk !!!

Last summer Sean Jr. and I witnessed a hawk swooping down and grabbing a Texas Spiny Lizard from the flower bed next to us.  This was mere feet from us and as you might imagine, seeing nature in action like this left an impression on Sean and I. He’s five years old. 

The hawk likely never saw us because we were blocked by a large Red Oak on his approach, and I am sure he was very focused.  It freaked Sean and I out, in a good way.  We just looked at each other in awe.

Well tonight I was out in the back yard checking the pool and I looked up to see the mysterious hawk.  I eased back into the house and grabbed my camera.  Light was dissipating fast. I managed to squeeze off a couple of ok shots with my Canon G11.

Now I need your help identifying our friend.  Anyone know what type of hawk this is?  It looks very much like an owl with that round head.  I see it flying daily as I walk my dog Elvis down the street and back. It has a very cool delta shaped tail.

Here’s another pic with the flash.  Makes him look pretty mean.  I am sure he is not happy I am interfering with his lizard hunt. I am not sure I like that much.  We are fond of the Texas Spiny Lizard.

Do any of you have an idea what type of hawk this is?