The Harrington family certainly went through hell and back. Their son was killed in a head-on car accident in Brookhaven, Long Island. They sued the Suffolk County Police Department, alleging that law enforcement's investigation into the accident was so deficient as to violate the due process clause.
The case is Harrington v. County of Suffolk, decided on June 4. As the Court of Appeals (Cabranes, Katzmann and Chin) tells us, the lawsuit claims that "the investigation that followed was inadequate in a number of respects. First, because of heavy rain, the responding officers allegedly conducted their investigation from a nearby diner rather than thoroughly combing the scene of the accident for evidence. Plaintiffs also allege that defendants, among other things, (1) failed to ascertain whether Guillaume had been under the influence of drugs or alcohol at the time of the accident, (2) failed to obtain a toxicology report, (3) failed to indicate in the police report that Guillaume was uninsured, and (4) improperly attributed the accident to weather conditions."
So is this a federal case? In order to have a claim under the due process clause, you need to show that the government denied a property or liberty interest without due process. The family says the property interest here is "receiving adequate police services" and a "proper and adequate investigation of the accident."
This is not a federal case. While property interests derive from a legitimate entitlement to state-created understandings or rules, that entitlement must be concrete and unique to the plaintiff/victim. It is not enough to show that the police department requires its officers to protect the community and enforce all laws and ordinances. Some discretion is inherent in all police work, and that discretion takes cases like this out of the due process universe. And the Supreme Court held in Town of Castle Rock v. Gonzales, 545 U.S. 748 (2005) that “the benefit that a third party may receive from having someone else arrested for a crime generally does not trigger protections under the Due Process Clause, neither in its procedural nor in its ‘substantive’ manifestations.”