I'm probably the only person to believe this, but I think there's a possibility that he hadn't set out that day to abduct or assault anyone. Don't throw any rotten eggs or tomatoes at me, I can't stand either! I was thinking he might just not be creative enough to make up a plausible story, so he more or less told the truth, but blocked out the parts that were hardest to admit to. Before I go any farther, I want to make it clear that what I'm about to say in no way excuses anything he did to MT during or after their encounter.
Maybe he had a lousy day, as many of us do, and decided to go for a drive to let off steam. When he saw MT running down the street looking happy, healthy and determined, it may have made him focus his anger/frustration on her. He drove by her several times while deciding what he wanted to do with her (like did he want to have a girl like her or did he want to destroy the symbol of what was missing in his life?) He really may have been dumb enough to think that she'd stop and talk with him if he approached her (but I really doubt it), but when she threatened to call the police it lit the fuse and he exploded. It wasn't because he was afraid of being deported or going to jail, and it wasn't that he felt rejected; it was more that it was one more frustration (the straw that broke the camel's back?) added to an already miserable day. That could account for why he doesn't appear to have had a plan laid out for what would happen once he got her.
I know many people who have tempers like that, but most haven't gone so far as to actually kill someone, yet. If he knew there was a possibility of totally losing control, he should never have gone near another person if he was in that kind of mood, and at his age, he should be aware of what he's capable of when he loses his temper. As I said, it wouldn't excuse anything he did, but it might help explain some of his weird actions. MOO