Firstly, the prohibition of murder is also ordained directly for the Muslims:
ولا تقتلوا النفس التي حرم الله إلا بالحق
And do not kill the soul which Allah has forbidden, except by right.
— Quran 17:33
Secondly, regarding whether a law from the Shariah of the previous nations is applicable to us, such a law will fall into one of the following ...