newshour correspondent spencer michels has the story. >> which one is this? reporter: this is richard muller and his daugherty elizabeth, a mathematician are not exactly house holes names. in the world of climate change where most scientists and a match smaller group of skeptics remain bitterly divided over their assessment of what's happening to the planet, richard muller has long been on the side of those who deny climate chan is happening. when he published an op-ed in

newshour correspondent spencer michels has the story. >> which one is this? reporter: this is richard muller and his daugherty elizabeth, a mathematician are not exactly house holes names. in the world of climate change where most scientists and a match smaller group of skeptics remain bitterly divided over their assessment of what's happening to the planet, richard muller has long been on the side of those who deny climate change is happening. when he published an op-ed in the ne "new york times" last moh saying he was no longer a skeptic, it captured national attention and sparked angry reaction on both sides of the climate fence perhaps most disturbing to some of his former allies was this conclusion. >> in our world, we attribute the warming from 175 to the present... 1753, to the present exclusively to humans not mostly. >> reporter: even those skeptics who accept that the climate is changing attribute it to natural cycles, but muller even claimed his study was more conclusive in that regard than any that came before. >> we really are in some sense comin

michelle is just hoping to make it through the day.2:55 &pit was the 21st when he got shot (tears bbgin) it was a month ago, 19 year ood lovell spencerilled. he was shot twice once in the chest. joys ?-queetion you see the shots and then what happens 5:40 he was running for his life a surveillance camera on a nearby building recorded thh murder.4:12 when i sawwthat i was devasted lovell made it to intersection of wilkens and monroe before he collapsed. a yelling for help came out of his home and craddled lovell until he diee.joy's puestion... what did he say to you?7:42 he said all he kpt telling lovell was hold on yoor mother is waiting on you your motherris waiting on you and for me o hear that at least he new i was really waiting on him and knowing my son wasn't coming back it was real hard for me :58 lovell expected to start school in six days. it was to pe his senior year. a goal he had struggled to achieve but looked forward to accomplishing. 18:02 i just miss his smile most f all i just miss him because lovell &pwas a loving caring person he would tryy t help anyone he cculd help:10 joy's question do you think his murder will