already a convicted sex offender. somehow his criminal history was never looked into. no background check on him apparently was ever done. and he wasn't alone. how is it possible? we're keeping him honest tonight. also head, dr. laura apologized for saying the "n" word several times on her show, but some are calling for a boycott. we go in depth on race with new details on a pilot study we commissioned, a surprising finding of what kids, even young ones, think of race and skin color and how you as a parent can help shape your child's perception of it. the government point man to the disaster admiral thad allen said bp will go ahead with drilling the relief well. they're considering other options. he said some tests indicate the planned bottom kill procedure to seal the damaged well may not be necessary. meantime, a man, a contract worker who supervised oil cleanup workers in mississippi, is in jail tonight, charged with raping another employee. a cnn investigation tonight uncovers his criminal history and raises questions about whether this incident could have been prevented by doing a simple background check. special investigations union