paramedics arrived but there was nothing that they could do for joe morrissey. last time i saw him. >> you saved yourself? you saved your son? >> but i did not save joe. i just couldn't. it was the most horrible thing to ever happen to me, to learn he was dead. >> it was a heartbreaking story. one that police came to believe. they cleared kay. >> we found no evidence to support us to believe that she was involved in any way in this murder. >> it is now up to investigators to find out who had done such horrifying things to this family. a family detective kendall believed had been targeted. but so far it was not making any sense. >> if it was something personal in nature, why not just come in, kill them and leave? >> the search for answers was on, and it would lead to a very different kind of family. >> police close in on a suspect, who seems to know a lot about the crime. >> coming up. >> honestly, i think you might be involved in this. >> okay. >> i never thought that it was someone who they knew. >> when "dateline" continues. n "dateline" continues it works nat