2G

Why do you think Joesbury was in Cambridge? Was this the right move for him?

Keeping an eye on Lacey. It's obvious he cares for her.

Considering Lacey's inexperience, I think it's a good thing for him to be watching her. I'm not sure whether he is doing this on his own time, though, or whether he has official sanction to do so.

He's watching out for Lacey. He knows that she's in over her head and feels partly responsible. Someone high up in the police is playing games with both of them. >2 Sergeirocks: I believe he is doing this on his own and will be in big trouble if he's caught.

I think he's observing her on his own and doesn't want her to know about it. He cares about it and he's worried about this whole undercover assignment.

I think he's keeping an eye on Lacey because he knows that he's using her as bait.

I agree! He's keeping an eye on Lacey.

At the time Lacey called him, Joesbury thought something like he had to be at a certain place in Cambridge in 10 minutes (I think). If he left now, he might run into Lacey since she was walking around the area. That made me think that he was assigned there to do something else, perhaps keeping an eye on a suspect involved in this situation. Of course, he's also keeping an eye on Lacey.