Berlin - A German nurse jailed for life last year for murdering two patients is now a suspect in at least 33 more deaths, investigators said Wednesday, adding that he has admitted to have killed even more.
The man, identified only as Niels H, 39, who was jailed for life in February 2015, has been found guilty of two murders and three attempted murders of intensive-care patients.
He had previously claimed to have killed more than 30 patients with lethal overdoses at the Delmenhorst hospital near the northern city of Bremen, which would make him one of Germany's worst post-war serial killers.
Analyses carried out on 99 exhumed patients at Delmenhorst suggest that at least 33 were killed by the nurse through lethal injections, investigators said on Wednesday.
But they added that the tall and heavyset man had also admitted to killing other patients at another hospital nearby - the Oldenburg Clinic, without giving a figure.
"We can say that the horror hasn't ended," said Johann Kühme, police chief of the city of Oldenburg.
Oldenburg prosecutor Thomas Sander added that in addition to the 33 likely cases, "we assume that the real number of victims is higher than that".
Hundreds of patient records will be examined at the Oldenburg clinic before deciding if mass exhumations of patient corpses would need to be carried out there as well.
The grisly case dates back to 2005, when a colleague witnessed Niels H injecting a patient at the Delmenhorst hospital.
The patient survived and Niels H was arrested and, in 2008, sentenced to seven-and-a-half years in jail for attempted murder.
Amid the media publicity, a woman then contacted police, voicing suspicion that her deceased mother had also fallen victim to the killer-nurse.
The authorities exhumed several patients' bodies and detected traces of the drug in five of them, declaring it either the definitive or possible contributing cause.
Nils H eventually admitted to injecting about 90 patients with the drug so he could then try to revive them and, when successful, shine as a saviour before his medical peers.
He said he felt euphoric when he managed to bring a patient back to life, and devastated when he failed.
After the shocking revelations of the nurse's murderous obsession, police and prosecutors launched a special forensic commission dubbed "Kardio" (Cardio) to look into other patient deaths.
The sweeping investigation is expected to take many more months.
The nurse had previously also worked at an elderly home and an emergency medical service.