"Jerry Springer" producer Jill Blackstone did not carry out her
sister's wish to end her life -- she murdered her ... at least
that's what law enforcement now believes. Our law
enforcement sources say Wendy Blackstone -- who was deaf
and partially blind -- did not want to end her life. During the
initial stage of the investigation we're told cops thought this
might have been a double suicide plan where Jill backed out
at the last minute, but now they believe it's simple murder.
TMZ broke the story ...
Wendy was found dead in their garage
and Jill had severe carbon monoxide poisoning from a lit
barbecue in their closed garage. We're now told in addition to
the coals under the grill, there was a metal trash can filled
with charcoal which had also burned. Cops determined early
on ... the suicide note found in Wendy's hand was not written
by her ... they believe Jill wrote it. Blackstone was arrested
for murder earlier this month but the D.A. felt there wasn't
enough evidence to make a case, so prosecutors sent it back
to the LAPD for further investigation. In the meantime, Jill
remains free. But now we're told ... after more probing, the
cops firmly believe it was murder.