In reply to Trangia:
Unfortunately too many car thieves have seen CSI and wear gloves when stealing cars these days.
DNA will be harder to use to ID the driver as hair samples can be argued to be from anyone in the car. You can put them in the car, but not neccessarily in the driver's seat, unfortunately.
Occasionally there is blood and/or saliva on an airbag, if it has been deployed, but even that has failed to secure a prosecution in at least one case I know of.
They should all be on a manslaughter charge if they can't pin it to a driver. Even if they pin it to a driver, the others should still be prosecuted.