Jesus is talking to a group of people about what might happen to them as individuals. The word "you" in "You have heard" and "I say to you" is plural. The command "You will not kill" is singular, but you may need to translate it as plural.
# it was said to them in ancient times
This can be stated in active form. AT: "God told our ancestors long ago" (See: [[rc://en/ta/man/translate/figs-activepassive]])
# Whoever kills will be in danger of the judgment
Here "the judgment" implies that a judge will condemn the person to die. AT: "A judge will condemn anyone who kills another person" (See: [[rc://en/ta/man/translate/figs-explicit]])
The "I" is emphatic. This indicates that what Jesus says is equally important to the original commands from God. Try to translate this phrase in a way that shows that emphasis.
It seems here Jesus is not referring to a human judge but rather to God condemning the person who is angry with his brother. (See: [[rc://en/ta/man/translate/figs-explicit]])
These are insults for people who cannot think correctly. "Worthless person" is close to "brainless," where "fool" adds the idea of disobedience to God.