From the BBC website:
**"Police have identified Syed Rizwan Farook, a 28-year-old US-born male, and Tashfeen Malik, a 27-year-old woman, as the two dead suspects. The FBI said it was not ruling out the possibility of terrorism but the situation was still being investigated."**
Reading the full account, I didn't get the feeling it was a terrorist-related incident, but you never know.