A San Antonio Police Department officer has been fired after shooting
a 17-year-old boy who was eating a meal in a McDonald’s parking lot,
the department said. The teen was charged with evading detention in a
vehicle and assaulting the officer. All charges have been dropped.
To prevail on a 42 U.S.C. § 1983 claim and defeat the qualified immunity defense in this context, a plaintiff must show that the law enforcement officer intentionally violated a well-established constitutional right.
To use force lawfully to prevent an escape of a suspected criminal, under the Fourth Amendment of the U.S. Constitution (as incorporated against U.S. states under the due process clause of the 14th Amendment to the U.S. Constitution), a police officer may use deadly force to prevent the escape of a fleeing suspect (whose status as a suspect is supported by probable cause) only if the officer has a good-faith belief that the suspect poses a significant threat of death or serious physical injury to the officer or others. Tennessee v. Garner, 471 U.S. 1 (1985).
In this case, the officer may have had a reasonable suspicion (the car looked similar to one he had been on the lookout for in connection with a car theft case although it was not actually the same one), although not probable cause (since there are many cars of the same color, make, and model of almost any type on the road at any one time), to believe that the car in question was stolen by a person who was not armed other than having the car. This probably doesn't meat the Garner test for constitutionality.
Alternatively, the use of force could be justified for self-defense or in the defense of others, if the car's hypothetical use as a weapon gave the officer probable cause to believe a suspect posed an imminent threat of serious bodily harm to the officer or others which the use of deadly force could prevent (as discussed in dicta in Garner).
In this case, the question of whether the officer was actually in imminent risk of serious harm, when the officer, in fact, never even came into contact with the car and was off to the side of it, would also be weak.
Shooting someone without either justification ought to overcome the qualified immunity defense.
A full qualified immunity legal analysis would cited also to binding precedents from the U.S. Court of Appeals for the 5th Circuit restating these U.S. Supreme Court enunciated constitutional right in circumstances as factually similar to this case as possible, to underline the fact that these constitutional rights are "well-established". Likewise, the plaintiff's lawyer would have to allege facts (which could be supported with affidavit testimony not contradicted by the videotaped evidence) that would support the arguments set forth above.