Transcript for Botham Jean, Atatiana Jefferson fuel outcry against police deadly force: Part 1
It could be me. It could be anybody. My son was the light in any dark room. Reporter: Two women at two very different stages of a long strangers who share a sorrow few of us know, and they are about to meet. I'm not nervous. I just don't really know what to say to her. Reporter: It had only been a few days since amber Carr had buried her sister, gunned down by a policeman in her own home. In your home? The place you go to get away from the world? Makes no sense. You can't put any sense to that. Reporter: Alison John's son botham also suffered that same fate. If I could ask her anything, it's how do you cope? How do you cope? Bottam John! Reporter: The names botham John and Tatiana, now a rallying cry. She wasn't killed. She was murdered. Reporter: Flash points in the national conversation on police and the use of deadly force. No justice, no peace! Reporter: Highlighted by a new study that found black men are 2.5 more times likely to be killed by police than white men. Botham John is one of that number. He was fully conscious of the stigma he bother as a man of He loved to dress well, and I would ask, what do you think that you must look the part every time? He said to me, mommy, I know what it is when I walk into an elevator and a little white lady pulls her bag closer to her. I dress well so that I am not mistaken. They can see your truth, lord. I pray for your hand of protection and guidance. Reporter: As an active church member, the 26-year-old's voice lifted up the confwragation. He was about forgiveness. He was about compassion. He was about reaching the underserved and underprivileged. Reporter: But none of that mattered on September 6, 2018. Jean was in his home watching TV. Amber guyger, says she accidently walked into Jean's apartment, mistaking it for her own and shot him dead. Up to now when I reflect on it, I still cannot believe that that could ever, ever happen. It's just, it's still difficult to understand that botham is not here. Reporter: Your son, a good Did all the right things. Reporter: This past September, the criminal case against amber guyger went to Why did you fire? I was scared. Whoever was inside of my apartment was going to kill me. And I'm sorry. I have to live with that every single day. Reporter: Amber guyger was found guilty of murder, sentenced to ten years in prison. I am much better. I feel much lighter. So I'm using this period now to heal. Reporter: The Jean family hired Lee Merritt to represent them in their ongoing civil My hope in all of these cases in holding police officers responsible is that a message will go out to the law enforcement community that they're not untouchable. There will be consequences if you pull that trigger and don't have the proper justification. Reporter: But just 11 days after guyger was convicted. Growing outrage in Texas. A woman killed by police in her own home. Reporter: 28-year-old Tatiana Jefferson was killed in ft. Worth, just 33 miles away from where botham Jean lived. You really can't make any sense of any of it. Reporter: Jefferson's family's fight for justice is just beginning. The wounds still raw. My family, we really shouldn't be at this point dealing with an assassination. Reporter: Why do you call it that? Because that is exactly what it is. Hi, my name is Tatiana Jefferson. She had diabetes, and she always talked about being the person to come up with a cure for diabetes. She was extremely strong. She was her own person. Reporter: Amber's 8-year-old son Zion was with her when she was kiltd. Adult trauma recounted through a boy's eyes. He said that he was sad. And I asked him why, why were you sad? He said well, the police shot aunty, and that was the first time that I had heard that. No one had given me any details on what happened. And I hated that my son had to be the one to tell me he was actually there to witness it. And could have been a target as I know I'm crying. And it looks like I'm sad, but I'm really angry. Police operator. 873. What's the address? I'm calling about my neighbor. Reporter: It all started with a concerned call to a non-emergency police line from a neighbor. Who later told us he was worried medical help was needed. It's not normal for them to have both of the doors open at this time of night. Reporter: The body cam footage shows the officer Dean walking past the front door. He said he was sitting up because they were playing video games. When three heard something outside she told him to lay down. Reporter: He went around the back of the house and approached a bedroom window. He heard him shout, put your hands up. Put your hands up! Reporter: The officer shot through the window. His split-second decision claim the Jefferson's life. If you could talk to the officer, what would you say to him? What was he thinking? What was he thinking? What was going through your were you afraid? Why were you afraid? Reporter: Lee Merritt found himself representing another loved one whose family message was shot in her own home. Reporter: Is it possible that officer Dean was just a young officer who made a terrible mistake and was not at his best. It is possible. It's possible that he was just poorly trained. Wasn't ready to be out on his own. Reporter: Aaron Dean declined our request for an interview. His lawyer said they had no comment. Dean had a promising career, commended in his personal files as a young officer work being at a level commonly seen from more experienced officers. In this video obtained by ABC news, here he is interviewing for the job back in 2017. I want to serve my fellow citizens in an up close and personal way. I like the action and adventure that I hear the stories told about that the job seems to promise. Reporter: Take note how he answers this fateful question. Will you be able to kill somebody if you have to? No problem. Reporter: Aaron Dean has not yet entered a plea. I respect the profession. They run towards the danger. But we amplify the idea that they get in fear in situations to the point that's unreasonable. Reporter: Coming up, inside the minds of police officers under stress. And, when amber and Alison meet for the first time, what wisdom is shared? For the long road ahead?
This transcript has been automatically generated and may not be 100% accurate.