Ruling on jury duty in a non-Islamic court in a non-Muslim country

Passing a verdict on a accused person whose case has been
brought to court and stating whether he is guilty or not guilty is regarded
as ruling and passing judgement. One of the conditions of ruling and passing
judgement is that it should be based on the Book of Allaah and the Sunnah of
His Prophet (blessings and peace of Allaah be upon him) even if it has to do
with passing judgement on kuffaar or judging between them. 

Allaah says (interpretation of the meaning):

“So if they come to you (O Muhammad
صلى الله عليه وسلم), either judge
between them, or turn away from them. If you turn away from them, they
cannot hurt you in the least. And if you judge, judge with justice between
them. Verily, Allaah loves those who act justly”

[al-Maa’idah 5:42]

“And so judge (you O
Muhammad صلى
الله عليه وسلم) among them by what Allaah has revealed and follow not
their vain desires, but beware of them lest they turn you (O Muhammad
صلى الله عليه وسلم) far away from some
of that which Allaah has sent down to you. And if they turn away, then know
that Allaah’s Will is to punish them for some sins of theirs. And truly,
most of men are Faasiqoon (rebellious and disobedient to Allaah)”

[al-Maa’idah 5:49]

Shaykh ‘Abd al-Rahmaan al-Sa’di (may Allaah have mercy on
him) said: 

“And so judge (you O
Muhammad صلى
الله عليه وسلم) among them by what Allaah has revealed” — this
verse is the one which is said to abrogate the verse “either judge
between them, or turn away from them”. But the correct view is that it
does not abrogate it, and that this indicates that the Prophet (blessings
and peace of Allaah be upon him) was given the choice between passing
judgement between them or not doing so, and that was because their aim was
not to refer to the truth for judgement. This verse indicates that if he did
pass judgement, then he was to pass judgement between them in accordance
with that which Allaah had revealed of the Qur’aan and Sunnah, and this is
the justice which is referred to above, in the verse in which Allaah says: “And
if you judge, judge with justice between them”. This points to what is
meant by justice, and that it should be based on the rulings that Allaah has
prescribed, which include the ultimate justice and fairness. Anything
contrary to that is injustice and wrongdoing. End quote. 

Tafseer al-Sa’di, p. 234 

Shaykh al-Islam Ibn Taymiyah (may Allaah have mercy on him)
said: 

No one has the right to judge between any of Allaah’s
creation, whether between Muslims or kuffaar or young men or armies or the
poor or anyone else, except in accordance with the rulings of Allaah and His
Messenger. Whoever seeks anything other than that is included in the words
of Allaah (interpretation of the meaning): “Do they then seek the
judgement of (the days of) Ignorance? And who is better in judgement than
Allaah for a people who have firm Faith” [al-Maa’idah 5:50] and “But
no, by your Lord, they can have no Faith, until they make you (O Muhammad
صلى الله عليه وسلم) judge in all
disputes between them, and find in themselves no resistance against your
decisions, and accept (them) with full submission” [al-Nisa’ 4:65]. End
quote. 

Majmoo’ Fataawa Ibn Taymiyah,
35/407, 408. 

The scholars of the Standing Committee for Issuing Fatwas
said: 

It is not permissible for a Muslim to work as a judge except
in sharee’ah courts which apply the laws of Allaah in all their rulings. End
quote. 

Shaykh ‘Abd al-‘Azeez ibn Baaz, Shaykh ‘Abd al-‘Azeez Aal
al-Shaykh, Shaykh Saalih al-Fawzaan, Shaykh Bakr Abu Zayd. 

Fataawa al-Lajnah al-Daa’imah,
12/136, 127 

It is no secret to anyone that the reference point for
passing judgement on people in the country asked about and — unfortunately
— in many Muslim countries is not the Qur’aan and Sunnah. Based on that,
the starting point for passing judgement on people — both Muslims and
kaafirs — is man-made laws, which are opposed to the laws of the Lord of
the Worlds. Based on that, it is not permissible to serve on the jury or
work in any other part of the courts which judge between people on the basis
of something other than that which Allaah has prescribed. 

And Allaah knows best.