Sorry for your friends loss.
I am in UK but our procedures in LE are similar to over there; it depends on a few things what happens next - do you know if there are any witnesses who can give descriptions of the car/driver? If not there is still plenty of enquiries that can assist in catching the driver.
1. Firstly CCTV is very helpful, it does not even need to be near where the accident occurred as nowadays the camera could be equipped with a system which records every car's number plate and stores it. This can be gone through by the investigating officers to narrow down the cars in the area at the approximate time of the accident. Most cars have up to date record of ownership on them.
2. House to house enquiries. Can be useful if someone saw/heard something that may be innocuous in itself but could assist with the bigger picture. Police may also set up a checkpoint at the scene of the accident and stop everyone driving through at the time of when the accident occurred (this can be useful if the driver was a regular commuter for instance). The drivers stopped will be asked several questions and these cross-checked against various things, the next point being one of them).
3. Paint transference. From the clothing of the daughter maybe paint (or glass fragments). This paint/glass is usually identifiable as used by the car manufacturer. Another way of narrowing down the make or even model of car.
4. Guilt. Most of these incidents are perpetrated by normal people, not hardened criminals and though they fled the scene initially, they may watch the news or whatever; hear about the death and become too guilt stricken and hand themselves in. Happens more than people would think; especially if they have told friends family who can also "grass" on them.
5. The car. It is actually quite difficult to get rid of a car easily; scrap yards keep records nowadays so if point 3 was used to trace the make/model of car the investigating officer could trawl yards to see if a car had been scrapped. Also, if it was dumped and set alight, most cars have VIN numbers which are etched to chassis in several places and can be linked to the owner.
In summary, there are several lines of enquiry the Police can and will investigate; forensics is a big thing as is the CCTV but there are probably other things that are or will be done so don't lose faith yet. I am not a traffic officer so I am sure there are lines of enquiry that I may have missed but I think the success rate in tracing the offenders in these sort of incidents is quite high from reading somewhere.
I hope this helps somewhat and hope the driver is traced; having young kids myself I am constantly worried as you cannot be looking after them all the time.
Ross
Last edited by RossUK; 09/18/13 02:44 AM.