How should one deal with a brother who works as a police officer, accepts bribes, and abandons prayer? Is his money lawful, and should one attend his wedding?

Taking a bribe is a grave sin, and abandoning prayer out of laziness, without denying its obligation, is considered by some scholars to be an act of disbelief that expels one from the faith. A person characterized by these traits is described as immoral (fasiq), and one should interact with him with the good manners of Islam, advise him, and invite him to goodness in the best possible way. If advice is not beneficial, then maintaining ties with him depends on the consideration of benefit and harm, as shunning an immoral person or a disobedient one is subject to what serves the greater good. As for his wealth, if he has wealth earned through lawful means, then his wealth is considered mixed, and it is permissible to deal with him and eat from it. Attending a wedding feast is obligatory if one is invited, provided there is no objectionable act present, and there is no impediment to eating from it unless it is directly from ill-gotten gains.