1993 – 1994 found victims Tangredi, Costilla, and McNamara remains (beaten, strangled and positioned) in/around Manorville, NY
1996 – human remains/body parts found in garbage bag in Fire Island, NY
2000 – found human remain parts dismembered Jane Doe 6-around Manorville, NY
2003 – found human remains parts dismembered Jessica Taylor-around Manorville, NY
2008 – human remains found in suitcase Tanya Rush-around Bellmore, NY
12/2010 – Melissa (missing 2009), Megan (missing 07/2010), Maureen (missing 2007) and Amber (missing 09/2010) found in burlap bags around Gilgo/Oak Beach, NY in December 2010
March 29, 2011- April 4, 2011 found four sets of human remains; 1 woman-ui Jane Doe 6-04/04/11-gilgo state park; 1 man- unid Asian 5-10yrs (possibly Yeung Tsui); 1 toddler- ui mom Jane Doe 6
Jessica Taylor-skull, hands, forearm found 3/29/2011 oak beach area
2011- Shannon found (missing 05/2010)
Hypothetically- if J. Bittrolff were involved in other murders besides 1993 victims, then the dates that the victims were found (assuming this was publicized in the media or perpetrator was privy to LE discoveries) may have caused the perpetrator to change his method of disposal. I.e. the 1993 victims were found, so when he was compelled to kill again he changed to garbage bags. But then the 1996 victim was discovered so he dismembered next victim and spread out parts (maybe perpetrator was working on project during 2003), etc.
The perpetrator possibly held onto Melissa, Megan, Maureen and Amber remains in burlap bags somewhere like summer cabin or shed until he could get rid of them during wintertime 2010, like around Thanksgiving when no foliage. If he held onto their remains for some time, maybe there is DNA from victims in the place (or he dismembered some maybe dna on construction/hunting tools used). Idk if he would have known about Shannon search in 2010 to throw off LE investigations. imo whoever is committing these crimes has some compulsive fetish or defect, but is also remorseful/conflicted (i.e. covering child), so hypo someone like J.Bittrolff may fit as he is a family man. Just some thoughts on possibilities given J.Bittrolff alleged to have murdered 1993 victims previously arrested for prostitution. This hypo would mean Shannon wasn’t related to others, but it doesn’t mean that she wasn’t killed by someone else.
If Melissa, Maureen, Amber or Megan were not dismembered, then the perpetrator may not really want/enjoy dismembering victims but does it out of necessity to avoid detection, just like burlap for camouflage i.e. erosion sandbags. jmo hypo and speculation.