. >> reporter: tom mauser, who wears his son's shoes as he makes his way through life on a mission. daniel, he fights to keep guns out of the hands of kids and criminals. he told us he actually met with sue klebold, and the meeting helped turn his anger into understanding.ight, she wants the families to know she's ready to offer anything else that will help. >> i don't want to impose myselfuse it has to be healing and what they need. >> reporter: so many psentenced to a life of grief, with no parole. after our interview is over, sheills of the rocky mountains and tells us sometimes she finds herself drawn to a place that has a s -- "it brought a nation to its knees. what have we learned?" it's the columbine memorial.>> i feel, kind of, unwelcome there. like, you know, of course. that perhaps i'm intruding.ay, if you go to that memorial, you just might see a grey-haired woman quietly, alone. >> i've spent quite a bit of time there. think.y. yeah. >> so much more about all the issues raised tonight on abcnews.com, and social media. and we will beain to the families of the victims, to

. >> reporter: tom mauser, who wears his son's shoes as he makes his way through life on a mission. for daniel, he fights to keep guns out of the hands of kids and criminals. he told us he actually met with sue klebold, and the meeting helped turn his anger into understanding. and she says tonight, she wants help. >> i don't want to impose myself about them and what -- and their healing and what they need. >> reporter: so many people, as someone said, sentenced to a life of grief, with no parole. after our interview is over, she walks outside in the foothills of the rocky mountains and tells us sometimes she finds herself drawn to a place that has a plaque with these words -- "it brought a nation to its knees. what have we learned?" it's the columbine memorial. >> i feel, kind of, unwelcome there. like, you know, of course. that perhaps i'm intruding. >> reporter: but someday, if you go to that memorial, you just might see a grey-haired woman - arctic air will start off your weekend ... and i'm also tracking this front and the accumulating snow it brings. sot) "he put the gun to the

. >> reporter: tom mauser, who wears his son's shoes as he mission. for daniel, he fights to keep guns out of the hands of kids and criminals. he told us he actually met with sue klebold, and the meeting helped turn his anger into understanding. and she says tonight, she nt the families to know she's ready to offer anything else that will help. >> i don't want t to imposmyself to do that, because it has to be about them and what -- and their healing and what they need. >> reporter: so many people, as someone saidid, sentend to a life of grief, with no parole. after our interview is over, she walks outside in the foothills of the rocky mountains and tells us sometimeses she fin herself drawn n to a pla that has a plaque with these words -- "it brought a nation to its knees. what have we learned?" it's the columbine memorial. >> i feel,l, kind ofunwelcome there. that perhaps i'm intruding. >> reporter: but someday, if you go to that memorial, you just might see a grey-haired woman sitting there -- quietly, alone. >> i've spent quite a bit of time there.