leita had been poisoned. the level of arsenic had in her system was three times higher than a lethal dose. >> it made you wonder who in the world it could be that was doing it. >> arsenic is a tasteless, odorless element used in rat poison. leita could think of only one person who could have done this, her husband olgie, was it possible that olgie poisoned his wife before he died? >> i really didn't think the man had the nerve to do a thing like that. >> to find out had, scientists looked for evidence in her hair. >> it turns out that the hair and in some cases toenails or fingernails are good indicators of body loads of certain elements. in particular, in the case of arsenic, it's often used as hair where it's concentrated in the hair. >> since hair grows approximately one-half inch per month and liita's hair was three inches long this gave scientists a six-month time line to see when leita was poisoned. each half inch piece of hair was tested with neutron activation analysis. >> neutron activation has some