A tabled LP system maintains a memo table of ``lemmas'' that were tried and possibly proved during query evaluation. We propose the concept of justifier for extracting sufficient evidence for the truth or falsehood of literals in a logic program, by post-processing the memo tables created during query evaluation. We give an efficient algorithm to implement such a justifier. Based on this justifier for logic programs, we show how to construct evidence for the presence or absence of tableaus in a tableau-based proof system. We provide experimental results, using the XMC model checker as a test case, which shows the effectiveness of the justifier in constructing succinct evidence in practice. Finally we discuss the role of the justifier as a powerful programming abstraction for encoding efficient algorithms as tabled logic programs.