>> does the saturation of color tell you got a lethal amount. >> oh yes, definitely. even the light pink color change means they're cyanide there is, significant toxic, if not lethal amount of cyanide present. >> autumn klein, had died of cyanide poisoning. no doubt about it she said. he grew even more confident when he reviewed the details of how she had collapsed and suffered. cyanide, once ingested can quickly starve the body of oxygen. >> so oxygen is on the blood, but it's not being utilized by the body. >> it was the trapped oxygen that turned the blood in autumn 's veins that vivid red. he also considered the 9-1-1 call. as her husband is begging for help autumn can be heard moaning in the background. >> now she's like having a seizure, jesus christmas sweetheart. >> luckasevic says that was likely autumn struggling to breathe. another important sign that cyanide was in her system. he knew he had a bizarre death