in it, sanders tells the stories of jennifer hopper and teresa butz and their life together. ers spent months with hopper and other family members. but he also examines the troubled life of their attacker. >> he was at the time, a nearly 24-year-old young man who came out of very difficult circumstances and had been living for quite some time with a serious mental illness that was not well treated, and he had bounced in and out of the criminal justice and mental health systems in the years before this crime, and had actually been engaged in a series of escalating, violent acts. >> brangham: your book documents so many different instances where people spent some time with isaiah and clearly recognized that this was a young man who was in serious trouble and needed some help, and yet that help was never coming. >> yes. i mean, as young as elementary school, he had teachers showing signs of concern, but it wasn't clear exactly what was going on with him. so, as an adult, for example-- his mother, at one point, when he was acting very worrisome, when she urged him to get care, he