. >> reporter: bob phillips was sergeant bob phillips. >> there was blood on the doormat. i remember that. >> reporter: she had been sexually assaulted, beaten and strangled. >> she was not covered up, but she naturally sunk into the english ivy. hard to see. >> reporter: her case is one of dozens that former detective bob phillips has been working for years to close. >> i actually started before i retired in 2000. took it upon myself to start. >> reporter: after he retired he volunteered to go through old case files. the county got a grant to pay him for two days a week. he looks for patterns in evidence. when he finds something he passes it on to the two active duty cold case detectives. >> our priority with the cold case is the physical evidence. with the dna data bases, the convicted offender data bases, the way they are now, you have a high likelihood of identifying an offender. in quite a few cases where we have identified suspects of these families, they've been appreciative that we didn't forget about it. >> reporter: bob phillips never forgets. >> i guess we have