Chris

Regarding the blue lights, it would depend on what they had been summoned there to do and whether they needed to shift at high speed to get there. They don't use their lights just to show they're answering a call. Lights and sirens are purely as a warning that a police car is moving at emergency speeds and other road users should give way.

In this case the suspect has already been detained by two unarmed officers and my guess is that other officers are attending to assist with securing the crime scene and begin interviewing neighbours.