"Eighty-four killings ... leave us speechless," Kuehme told reporters. "And as if all that were not enough, we must realize that the real dimension of the killings by Niels H. is likely many times worse."
The fact that the cases go back many years and people may struggle to remember the exact details of their loved ones' deaths hurts authorities' ability to determine an exact number, Kuehme said.
He faulted local health authorities for being slow to act.
"If the people responsible at the time, particularly at the Oldenburg clinic but also later in Delmenhorst, hadn't hesitated to alert authorities " for example police, prosecutors "" Hoegel could have been stopped earlier, Kuehme said.
Authorities are already pursuing criminal cases against former staff at the two facilities.
Hoegel worked at the Oldenburg hospital from 1999 to 2002 and in Delmenhorst from 2003 to 2005.
Kuehme said other medical workers at Oldenburg were aware of an elevated number of resuscitations, and initial indications of possible wrongdoing by the nurse in Delmenhorst emerged as early as April 2003.
During his trial, Hoegel had said he intentionally brought about cardiac crises in some 90 patients in Delmenhorst because he enjoyed the feeling of being able to resuscitate them.
He later told investigators that he also killed patients in Oldenburg.
Prosecutors are expected to try Hoegel on at least some of the additional killings but Germany's judicial system does not allow for consecutive sentences, so future convictions won't affect his life term.
The identities of the suspected 84 victims haven't been released. There was no immediate comment from any representatives of victims' families.
- AP