Typically, officers will file an accident report that will document details of the accident, such as skid marks, that will hint at possible speed. Experts in crash forensic will be able to evaluate scenes of accidents as well, and their training will enable them to understand how the remains of the accident may prove that a driver was speeding. Additionally, street cameras and eyewitnesses may be able to verify that a truck driver was exceeding the speed limit. Street cameras could provide video evidence, and while eyewitnesses may have their memory of an accident questioned, they could also have video evidence of their own. Your attorney will be able to access police reports and records that will contain the information for these eyewitnesses, allowing them to be called as a witness during trials.