The issue, according to the Bush Justice Department, is that police are not supposed to shoot people just for running away when they say "Stop, police!"
Assistant U.S. Attorney Bill Baumann, who prosecuted the case, told reporters that the law does not give law-enforcement officers the right to use "deadly force to stop a car unless it poses an imminent threat to the officer or another person. If the car is going away from you, it's not even a close call."
The exceptions to this rule are when the "fleeing felon" is dangerous, so letting them run means potentially letting them run and kill someone, and (obviously) when there's reasonable belief that they aren't really running away, but just trying to get to a position of advantage where they can attack again.
Either one might have applied here, but the Bush Justice Department insisted on prosecuting the deputy involved.
U.S. Attorney Johnny Sutton, appointed in October 2001 by President Bush, said Hernandez fired shots at the vehicle as it sped away "knowing it was occupied with the nine individuals," at least seven of whom were illegal aliens — some of whom later were called to testify for the government.
Has the Justice Department made any attempt to deport these people now that they've testified?