Of the 44 journalists killed in 2010 for whose deaths a key advocacy group was able to find a motive, almost a third of them covered corruption.

The Committee to Protect Journalists, or CPJ, which defends media workers around the world, tracks and investigates the circumstances surrounding the deaths of journalists, and it created an interactive infographicshowing where, how and why most were killed last year. Thirteen of the 44, or 30%, were corruption beat reporters. Other top beats of journalists killed included politics,...