When regression tests fail unexpectedly after a long session of editing, it may be tedious for programmers to find out the failure-inducing changes by manually inspecting all code edits. To eliminate the expensive effort spent on debugging, we present a hybrid approach, which combines both static and dynamic analysis techniques, to automatically identify the faulty changes. Our approach first uses static change impact analysis to isolate a subset of responsible changes for a failed test, then utilizes the dynamic test execution information to rank these changes according to our proposed heuristic (indicating the likelihood that they may have contributed to the failure), and finally employs an improved Three-Phase delta debugging algorithm, working from the coarse method level to the fine statement level, to find a minimal set of faulty statements. We implemented the proposed approach for both Java and AspectJ programs in our AutoFlow prototype. In our evaluation with two third-party applications, we demonstrate that this hybrid approach can be very effective: at least for the subjective programs we investigated, it takes significantly (almost 4X) fewer tests than the original delta debugging algorithm to locate the faulty code.