A conflict of interest can come in a situation where an individual has competing interests or loyalties because of their duties to more than one person or organization. A person with a conflict of interest can't do justice to the actual or potentially conflicting interests of both parties. For instance, if internal auditor, who is in a position of trust, has a competing professional or personal interest.
Another example is if a person have a loyalty to an employer and also loyalty to a family business. Each of these businesses expects the person to have its best interest first. Thus, the conflict .
Such competing interests can make it difficult to fulfill his or her duties impartially.
A conflict of interest exists even if no unethical or improper act results.
Explanation: A witness; this is an individual who is required to come to court of law to answer questions about a case. answers given by a witness in court are are regarded as evidence. Before a witness is allowed to give evidence to a case he/she swears an oath promising to tell the truth. The most common type of evidence is known as testimony from an eyewitness, this is what he/she witness, saw or experienced.
legal system would be very subjective depending on who committed the crime, who was the victim, where it was, etc. It would be very localized and unfair.