He would then measure their blood pressure and suggest they needed an injection which anaesthetized them .
In 1997 Petrov began robbing his patients by visiting their home , unannounced , and usually in the morning when relatives would be at work .
Petrov would then measure relatives ' blood pressure and suggest they needed an injection which anaesthetized them .
In 1997 Petrov began robbing his patients by visiting their home , unannounced , and usually in the morning when relatives would be at work .