Ruling on working as a defence lawyer

Defence also means protection, and if
a person defends and protects evil then undoubtedly this is haraam,
because it means that he is falling into that which Allaah has forbidden:

“but do not help one another in sin and
transgression”

[al-Maa’idah 5:2 – interpretation of
the meaning]

But if he protects and defends good, then this is a praiseworthy
kind of protection as enjoined in the aayah:

“Help you one another in Al‑Birr
and At‑Taqwa (virtue, righteousness and piety)”

[al-Maa’idah 5:2 – interpretation of
the meaning]

On this basis, whoever has prepared himself
to do that must, before taking on a specific case, examine and study
it. If the one who is asking for his defence is in the right, then he
should take on the case and support the truth and the one who is in
the right; if the one who is asking for his defence is not in the right
then he may also indulge in a case of that nature but the lawyer may
go against the wishes of the one who is seeking his defence in the sense
that he is protecting this person to prevent him from falling into anything
that Allaah has forbidden, and he does not defend him in the way that
he wants. That is because the Prophet SAWS (peace and blessings of Allaah
be upon him) said: “Help your brother whether he is a wrongdoer or one
to whom wrong is done.” They said, “O Messenger of Allaah, (we know
what it means to help) the one to whom wrong is done, but how can we
help him if he is a wrongdoer?” He said, “Stop him from doing wrong
to others, that is how you will help him.”

If he knows that the one who is seeking
his protection has no rights then he must advise him and warn him and
put him off getting involved in this case; he should explain to him
what is wrong with his claim so that he will give it up out of conviction.