Driving & Driving Test Tips: Reconstructionist, speed calculation, skidmarks

Question
I was wondering are you able to determine speed calculation
from accident? speed limit on the highway is 50mph.

Involve in an accident.  SUV was heading North through the intersection, when a car  heading South dart out to make a left turn in the path of the SUV. THE SUV didn't have enough time to react to stop in time because , while half through the intersection is when the car turn . Police ask did the SUV use their breaks because there was no skid marks left from the SUV, but there was skid marks left from the turning car. Police said the SUV had pushed the car at least 100ft out of the intersection. are you able to determine how fast the suv was driving?
what does no skid marks indicate? Police said he believe suv was speeding but doesn't have a recording  radar.  

Thank you.. Happy New years

Answer
yes speed at impact can be calculated by post impact skidmarks and trajectories and at rest positions, or by crush analysis.  It can not give a pre-impact speed down the road if a vehicle had braked for some distance unless there are skidmarks.  But a vehicle can slow down without leaving skidmarks leading up to an impact.