Editor's Summary: Following the issuance of two significant decisions in 2006 addressing whether claims of "probabilistic" injury are cognizable for Article III standing purposes, the U.S. Court of Appeals for the District of Columbia (D.C.) Circuit has continued to develop its jurisprudence on this important constitutional question. In this Article, Cassandra Sturkie and Suzanne Logan examine how the D.C. Circuit has analyzed these "increased-risk-of-harm" claims in four cases decided between November 2006 and January 2008. They consider how the court's analysis has varied depending on the nature of the case, focusing on the court's decision to sidestep claims of increased risk in an environmental case. They give special attention to Chief Judge David B. Sentelle's repeated criticisms of such claims before he became Chief Judge in February 2008, and consider what his leadership might mean for this issue. Finally, they offer new lessons for environmental law practitioners, their clients, and governmental litigants.