A Berkeley chemical engineer who suffered years of unexplained illness discovered through a spy camera from Amazon that her coworker, David Xu, was poisoning her food and water with cadmium, a toxic heavy metal for nearly 18 months between 2017 and 2019. The victim experienced significant health problems and at times required emergency care at a hospital. Newly released video shows Xu appearing to put a substance in her water bottle in 2019. Xu was arrested that year and charged with attempted murder and two counts of poisoning, offenses that could have sent him to prison for life. But under a plea deal, the attempted murder charge and one poisoning count were dropped. Xu pleaded no contest to one felony poisoning charge and received two years of probation, with credit for one day served. He completed probation in March and is now seeking to have his felony conviction dismissed.