.....
As far as bittrolff being a beer drinker and cops assuming he was paranoid for not throwing his beer bottles out at the curb... is it possible he might recycle them himself or return them to the beer distributor when he gets more beer? Id say so, lots of people do that.
That's actually an interesting question in a roundabout way.
A lot is not known about this case yet, and one of the most interesting things is the dna that was used as a sample to supposedly tie Bittrolff to the girls who were killed.
So going a little earlier than the beer bottles, it seems likely that a Suffolk cop or cops did have a sperm sample from Bittrolff, that's my guess. But...
1) The sperm sample that they had, and which was testified about, was in unusually good condition. In fact detective Leser remarked about how unusual that was. The girls bodies were found outside in chilly weather, but neither was found quickly enough that a person could consider that evidence as having been removed from the bodies shortly after the sex act. In other words the prosecution did not argue that the sperm was found within a short time of having been deposited. They argued that the women were killed shortly after sex, then the bodies lay for a while and the sperm stopped degrading once the women died. It seems very unlikely.
2) Whatever sperm sample they obtained later, probably from Bittrolff, was what they bet everything on. In other words somebody acquired a sperm sample, then they had a piece of evidence that had to be tailored to the crime. The problem might have been that a new sperm sample is going to be somewhat different than one that has been in a body for a length of time. The prosecution did get an "expert witness" to clean that up.
First what the detective said in an interview
http://www.indyeastend.com/Articles...7-THE-COP-WHO-TRACKED-A-COLD-CASE-KILLER.html
"I soon learned biological things I never knew about the female body," says Leser. "When semen enters a woman's body her system reacts as if it's a foreign invader and attacks it, breaking it down and degrading it fairly quickly. In order for as much spermatozoa with tails still attached to be present in each victim meant that she must have died within hours of the sex. And the DNA in the semen in both cases belonged to John Bittrolff."
He is going into some detail about the quality of the sperm, trying to explain why a lot of the tails were still attached.
Then the expert witness at trial
http://www.newsday.com/long-island/...xamined-by-defense-in-murder-trial-1.13712124
The day after Suffolks chief medical examiner used sperm density to explain to a jury how soon after sex two women were killed, he conceded during cross-examination Tuesday that numerous factors could affect the reliability of his estimate....
Caplan earlier had testified that the density of sperm cells he found in different areas told him how long before death they could have been left there. He estimated that Tangredi was killed less than 26 hours after sex and that McNamee likely died less than 24 hours afterward...
And we'll throw in a science website to make things balanced
http://harfordmedlegal.typepad.com/forensics_talk/2006/12/dna_semen_analy.html
Non motile sperm may normally be found up to 3 days after intercourse, and sometimes up to 6 days later in the cervix. Intact sperm (with tails) aren't usually found after 16 hours post intercourse but have been found up to 72 hours.
So we have detective Leser who states explicitly that a lot of tails were present. A scientific type might assume from that that the sex act probably occured within 16 hours of the body being found, which would not work out in these cases probably.
The forensic expert goes in a different direction, using a slide supposedly prepared in 1994 to estimate based on density.
Since it isn't likely that detective Leser was lying about having a sperm sample with a lot of tails attached, which matched Bittrolff's dna, a guess might be that Bittrolff was induced to give a sperm sample by some woman perhaps with that task assigned to her. Normally, in most places, that would be an absurd assumption. Most police, even corrupt ones, don't go to that much trouble to frame somebody.
But in this case, that exact kind of 'framing' is exactly what the police chief was known for. It was his signature.