Planning a homicide? Watch CSI!!!

When Tammy Klein began investigating crime scenes eight years ago, it was virtually unheard of for a killer to use bleach to clean up a bloody mess.

Today, the use of bleach, which destroys DNA, is not unusual in a planned homicide, said the senior criminalist from the Los Angeles County Sheriff's Department.

Klein and other experts attribute such sophistication to television crime dramas like "CSI: Crime Scene Investigation," which give criminals helpful tips on how to cover up evidence.

Prosecutors have complained for years about "the CSI effect" on juries — an expectation in every trial for the type of high-tech forensic evidence the show's investigators uncover. It also appears the popular show and its two spinoffs could be affecting how some crimes are committed.