It was my understanding the the GF was not talking to the SPD or cooperating with them. Pam Bondi ,the Florida AG was on the Piers Morgan show on 3/27/12. This is what I found:
http://transcripts.cnn.com/TRANSCRIPTS/1203/27/pmt.01.html
MORGAN: Yes, I mean, look, I am encouraged by what you're saying. It's good that a senior lawmaker in Florida is saying all this, but in the end, you know, I remain like many people absolutely bemused that somebody can shoot somebody in cold blood, an unarmed young teenager.
And so, I mean, I just think with your legal training and your legal background on what appears to be a very empathetic attitude towards this case, it might be quite powerful for the attorney general of Florida to say publicly, you know what? This guy should be arrested. He should be interviewed under caution and he should, if necessary, face charges. But he should be at stage one of the legal process of being under arrest.
BONDI: Well, what we've done is appoint a special prosecutor. And that's what she's doing.
Conducting a thorough investigation because we need to get Trayvon's girlfriend to cooperate which I don't know if was happening previously. And they may have had good reason for that. But she's cooperating now. And again, a thorough investigation is being done to ensure that justice is sought for that family.