Page 2 - Envelope Flap News Today : Breaking News, Live Updates & Top Stories | Vimarsana

Looking at the resulting types that she donated to both of her children. >> chris's dna profile was on file as part of his military records. scientists cut a small piece of envelope flap, put it into a solution which dissolved everything but the human cells and performed a pcr dna test. the results? the dna test revealed chris had licked the envelope flap. >> placed that letter in the envelope and sealed it himself. that is the only reason his saliva was on those envelopes. because dorothy had no intention of committing suicide, that those letters were a cry for help, and that chris used those...

Mistake. he licked the envelope flap and left enough saliva for dna testing. police now had the dna profile of the zodiac killer. the letter also included another clue. >> i knew it was a code. it was a nine towers because there were nine victims. and i wrote down all the different symbols. and i think i had 23. very close to an alphabet. and then i did something called a frequency count. which is, you write down how many times each letter is used. because, for example, e is the most commonly used letter in the alphabet. >> kieran crowley's father-in-law had been a code-breaker in world war ii...

>> the cost of the dna testing, approximately $7,000, would have to be paid by paula nawrocki. blood samples from both paula and her husband were sent to a local dna lab along with the threatening letters and the envelopes. >> the amount of dna that winds up on the back of a stamp or an envelope flap depends on how hard you lick the envelope, how much cells that you shed from the inside of your mouth. there are variables that's hard to predict exactly what the value would be. but it is there. in some cases there is more dna than others. >> first scientists use steam to remove the dna from each...

With this letter he made a mistake. he liquid the envelope flap and left enough saliva for dna testing. police now had the dna profile of the zodiac killer. the letter also included another clue. >> i knew it was a code. it was a nine towers because there were nine victims. and i wrote down all the different symbols. and i think i had 23. very close to an alphabet. and then i did something called a frequency count. which is, you write down how many times each letter is used. because for example e is the most commonly used letter in the alphabet. >> karen crawly's father-in-law had been a code ...

There was no postmark on the envelope, which meant it had been hand delivered. >> miriam is frantic about this. she is convinced that the killer is now out to get her. >> the simple block lettering made handwriting analysis impossible. there were no fingerprints on the envelope or the letter. the envelope wasn't sealed, so there was no saliva on the envelope flap and no dna to recover. and the barcode on the back of the card was missing. >> it had been cut out, and -- as if somebody knew we might want to try to trace that greeting card and find out where it came from. >> investigators contacte...