"The boy understands and does not kill."
Translation:Băiatul înțelege și el nu omoară.
If the boy does not kill /another person/, then I would say that 'ucide' is better. My understanding is that 'a omorî' refers to killing things in general; e.g. people, animals, plants, bacteria - and that 'a ucide' is used more specifically for the crime of murder.