What would the police do in this (fictional) car accident?

Well, first of all let me say that this scenario is one heck of a story for you to conjure up in your young mind. That being said, there are many questions that one would need to ask and confirm before decisions can be made by the responding police officer. So, here we go. With the limited facts you presented in this scenerio, at the least, the minor would be cited for not having a drivers license. Now the other cirstances are uncertain. The adult driver who was distracted and initially struck the pedestrian may or may not be charged with striking a pedestrian in the roadway based on the evidence and investigation at the scene. If the driver does not admit to being dsitracted, how is the officer to determine what actually caused the accident? Well, you have to look at the scene. Are there other parked cars or trucks that could have obstructed the driver's ability to see someone suddenly darting out into traffic? Was it daylight, nightime, dawn or dusk? Was it pouring rain or extremely sunny? Were drugs and/or alcohol involved? Without the driver's admission of negligence and no other cirstances that would indicate fault on the part of the driver, no charges would likely be lodged against the adult driver. That is so long as all licensing and required insurance information is in compliance with all appropriate laws and/or ordinances. Now the minor will be cited for no drivers license and any other appropriate license/vehicle violations. However, unless the minor admits to tailgating or any other conduct that would constitute some act of negligence, avoiding an accident and striking a pedestrian already in the roadway would not likely result in charges for that issue. However, motorists are requesired to be in control of their vehicle at all times and a copper should be able to ask the right questions to get to the bottom line as to what happened and why. If both parties, due to a thorough investigation done by a sharp police officer, admit wrongdoing that could result in one or both parties being charge with more serious offenses. But now we're getting into causes of death and interrogation techniques, locating witness etc. There are way too many questions that need be asked and answered before any concrete decison could be made based on the scenraio you presented here.