according to the record and her hoodie, or what she was wearing. >> and according to wysocky, there is something else that stands out. as seen in this animation reenactment of brenda's statement to police. >> we take the initial police report word for word, and make an animation to see if it's possible. >> on the night in question, brenda claimed that she was sitting at the foot of the bed and jonathan was in bed. >> the person that's going to commit suicide generally doesn't dress for bed. get in, pull the covers up and shoot themselves. >> and there's the final resting position of the gun. >> when you shoot a gun, there's just a little kick. it doesn't neatly settle right next to your body, pointing at your toes. it's lined up. that doesn't happen. >> plus, there's where he was shot. >> the angle was right at his heart, and i believe she was shooting him in the heart because he broke her heart. after a long, painful investigation, the cruz family and the private investigator turn over their findings to police. yet no murder or other criminal charges were brought against brenda kelly.

to sheila wysocki, the frightened coed turned mom turned private eye.e about to finally fall into place. you still focused on the theory that russell buchanan did it and got away with murder? oh, absolutely. absolutely. found out he was still in dallas, that he was actually a professional. and i kept thinking, why is this man having a good life after he had murdered angie? it was going to be solved, and russell was going to go to jail. josh mankiewicz (voiceover): well, just a minute. sheila's persistence breathed new life into a case that sat cold for nearly 24 years. now, the investigation was about to take a stunning turn. coming up. the detective said we got him. my mind immediately went to russell. who else could have done it? craig melvin (voiceover): good question. but the last thing she was prepared for was the answer, when "dateline" continues. [dramatic music] dupixent can help people with asthma breathe better in as little as 2 weeks. so this is better. and this. dupixent is an add-on treatment for specific types of moderate-to-severe asthma.