A few things, Longoria is super hard to search in Texas. I knew that might be the case (I grew up there.)
It is totally possible to have a child 16-18 by him. In Texas "we start 'em early", I think my grandpop used to say that.
Some stats:
http://www.foxnews.com/story/0,2933,380323,00.html
Also, if I remember correctly someone pulled a few last names from the houses on the 1800 block. There are a few similar names to some of the kids at the Highschool. (Not saying this is related, they are very common names. Well, some of them.)
What happened to this "party" that she was going to? If that wasn't the case, clearly there has to be some sort of internet/phone trail! It's not like he was a complete stranger and picked her up and she got into the car willingly.
At this point, I am banking that someone else picked her up. And, knowing a little that I know, this small party was at Longoria's house.
We had this house on the block in Texas, I was in Junior High, and older children would go there and party 24-7 because the parents felt it was better to party under supervision than to be out on the streets doing it. I was NEVER allowed to go there, I am very thankful now that my parents were strict like that.