i said, let's see if i can find picture hanging wire. i found some, but not that. i called everywhere. i called the manufacturers, do you sell a thinner wire? >> very uncommon? >> very uncommon. >> so uncommon, of all the picture hanging wire sold, this particular wire only accounts for 1% to 6% of sales. >> it's that rare. yet, that's what is being used to build the garrote, and that happens to also be what doug had access to because of his mom's painting. >> not like dna, of course, but what they call a class match. was it enough along with everything else to get lewin to take the case to course? >> i got done with the work on the wire, went to work on the alibi, with the work on the garrote, i felt we had a fileable case. i brought it to john. >> now, at this point, a more conservative prosecutor might have told him forget it, but lewin likes tough circumstantial cases. he said yes and took the case to his boss at the district