(CNN) - A former nurse on trial in northwest Germany admitted to murdering 100 patients.
The confession makes 41-year-old Niels Hoegel one of the country's deadliest post-war serial killers.
Hoegel is accused of killing his patients between the ages of 34 and 96 with various non-prescription drugs.
He said it was all an attempt to show off his resuscitation skills to colleagues and to fight off boredom.
Hoegel worked at two hospitals in northern Germany between 2000 and 2005.
He's already serving a life sentence for six convictions, including homicide and attempted homicide.
Those convictions led authorities to investigate hundreds of deaths.
Hoegel's trial is expected to continue until next May.
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