As of this morning, the count appears to be five officers dead, seven more injured. The shots did not come from the protestors, but from elevated positions in a car park. Police cornered at least one suspect, who took his own life. What else do we know about this? Almost nothing. The "suspect" whose photo was released last night (A) turned himself in as soon as he realized he was being sought, and (B) evidently had nothing to do with it, and (C) will very likely have people who saw his picture and are still thinking that he was one of the shooters.
Most of what gets reported during and immediately after an event like this is speculation, not fact. News article this morning is reporting that the police aren't sure what prompted the attack, and aren't even sure they have all the suspects. So, please, PLEASE be very cautious about what information you pass along and what you take to heart. That's especially important in the midst of something as horrible as this.
EDIT: No sooner had I posted this than I saw another article indicating the suspect in the car park had not taken his own life; the police apparently killed him while using one of the bomb-defusing robots. So even the clearly-reported "facts" aren't always right.