How does this idea sound for a romance?

Well, it's not really a romance...but i literally just thought of this now. It'll also probably be a short story: A British girl goes to Washington D.C. with her history cl. She's not a loner, per say, but she doesn't like an awful lot of people in her cl. So, she wanders away and explores the White House. Whilst strolling around she bumps into this guy, who looks pretty suspicious. They way he walks, him only looking down, looking tired and nervous. She's worried about him, but also has a very bad feeling about him, so she follows him. After a while, he notices her following him, and when they get to a desertedish (there's a janitor cleaning the floor) corridor, he confronts her and goes kinda psycho. After a bit, the janitor shouts at him to lay off or something. The guy's very twitchy and scared anyway, and this takes him by surprise. He pulls a gun out and shoots the janitor. The girl freaks out, but the guy has a complete breakdown, regressing to a little boy almost. She's never has a strong sense of moral, and whilst horrified that he killed a man, takes pity on him. She throws the gun into the water bucket, forces out some tears, tells him to follow her lead (though he doesn't react) and as the security come running round the corner, pretends she and him are innocent bystanders. He's confused she's helping him, but through the questioning he stays silent whilst she supplies the police ans security fake names and stories. After the night's questioning she gets a liftwith him back to the hotel she's staying at with her cl. Outside the hotel, he has a sort of heart-to-heart with her about why he was there with a gun, his life blahblah (i haven't decided yet, probably some cabinet guy ruined his life and he wanted revenge...). Because of what she did for him, he trusts her enough to tell her his real name. After all that, he walks away, and she realises what she did was wrong, despite the sort of pity-love she feels developed for him, and so calls the police. Well, what do you think?