and something else perhaps very significant. there was blood on the doorknob of the door that led from the main house into the backyard garage. reporter: the blood became evidence item number 805 collected days after carol s death. and whose dna was mixed with carol s blood? jim knapp s dna. just like the thumbprint, the question becomes when did jim knapp s dna get put on that door handle? reporter: robertson clearly had his suspicions. and steve s sister sharon did too. so you ve felt all along that jim knapp should have been a suspect and wasn t. he should ve been investigated. there were a lot of red flags that were concerning. reporter: knapp told sheriff s deputies he was nowhere near carol s house when the murder happened. he was at his ex-wife s place, miles away, babysitting his son. didn t they find out the alibi, in fact, was pretty solid? no.
and something else, perhaps very significant. there was blood on the doorknob of the door that led from the main house into the backyard garage. reporter: the blood became evidence item #805 collected days after carol s death. and whose dna was mixed with carol s blood? jim knapp s dna. just like the thumbprint, the question becomes when did jim knapp s dna get put on that door handle? reporter: robertson clearly had his suspicions. and steve s sister sharon did too. so you ve felt all along that jim knapp should have been a suspect and wasn t. he should ve been investigated. there were a lot of red flags that were concerning. reporter: knapp told sheriff s deputies he was no where near carol s house when the murder happened. he was at his ex-wife s place, miles away, babysitting his son. didn t they find out that the alibi, in fact, was pretty solid? no.
doing with those documents? and something else, perhaps very significant. there was blood on the doorknob of the door that led from the main house into the backyard garage. reporter: the blood became evidence item #805 collected days after carol s death. and whose dna was mixed with carol s blood? jim knapp s dna. just like the thumbprint, the question becomes when did jim knapp s dna get put on that door handle? reporter: robertson clearly had his suspicions. and steve s sister sharon did too. so you ve felt all along that jim knapp should have been a suspect and wasn t. he should ve been investigated. there were a lot of red flags that were concerning. reporter: knapp told sheriff s deputies he was no where near carol s house when the murder happened. he was at his ex-wife s place, miles away, babysitting his son. didn t they find out that the
doing with those documents? and something else, perhaps very significant. there was blood on the doorknob of the door that led from the main house into the backyard garage. reporter: the blood became evidence item #805 collected days after carol s death. and whose dna was mixed with carol s blood? jim knapp s dna. just like the thumbprint, the question becomes when did jim knapp s dna get put on that door handle? reporter: robertson clearly had his suspicions. and steve s sister sharon did too. so you ve felt all along that jim knapp should have been a suspect and wasn t. he should ve been investigated. there were a lot of red flags that were concerning. reporter: knapp told sheriff s deputies he was no where near carol s house when the murder happened. he was at his ex-wife s place, miles away, babysitting his son. didn t they find out that the alibi, in fact, was pretty
reporter: what was jim knapp doing with those documents? and something else, perhaps very significant. there was blood on the doorknob of the door that led from the main house into the backyard garage. reporter: the blood became evidence item #805 collected days after carol s death. and whose dna was mixed with carol s blood? jim knapp s dna. just like the thumbprint, the question becomes when did jim knapp s dna get put on that door handle? reporter: robertson clearly had his suspicions. and steve s sister sharon did too. so you ve felt all along that jim knapp should have been a suspect and wasn t. he should ve been investigated. there were a lot of red flags that were concerning. reporter: knapp told sheriff s deputies he was no where near carol s house when the murder happened.