What the Bible says about Legal weight of two witnesses
(From Forerunner Commentary)

Matthew 8:28-34 Jesus stayed in Gadara only for a few hours, but during that time, He came across two demon-possessed men (Matthew 8:28-34; Mark 5:1-20; Luke 8:26-40). Although Matthew's account mentions two men, and Mark and Luke record only one, no contradiction exists between them. The simple explanation is that one of the men, acting as their spokesman, was more prominent and aggressive, and thus more noticeable than the other. Perhaps Matthew, directing his gospel toward Jews, emphasized their number, knowing the legal weight of two witnesses (Deuteronomy 17:6; 19:15). Martin G. Collins The Miracles of Jesus Christ: Two Demon-Possessed Men Healed (Part One) Related Topics: Alleged Contradiction in Scripture | Contradiction in Scripture, Alleged | Exorcism of the demons in Gadara | Legal weight of two witnesses | Miracles of Jesus Christ: Exorcism of Demons | Two Witnesses

Matthew 18:16 Jesus quotes this principle of appropriate judgment from Deuteronomy 19:15. How do we go about this? We find another church member, or two if necessary, and we ask them to become involved. They should be members who are not gossip-mongers and whose word is reliable. An unbiased person is best in many ways. However, on the other hand, it is wise to have a person who to some extent agrees about the offense. Perhaps he has been offended in a similar way by the same offender in the past. This is where it can become tricky. Be very careful! Do not be hasty! It should not be our intention to start a war over this. Nor do we want to split the "protective island" of our congregation into two opposing camps. Neither do we want to be accused of gossip. At the very beginning of the first step, we should have advised the offender that we were bringing this to him in accordance with Jesus' instructions in Matthew 18. If Step Number One does not work, then we should tell him again that, according to Jesus' command, we need to take it to Step Number Two, and that we wish to involve another person or persons. Be gentle! Be diplomatic! Now, what if the offender refuses to resolve the problem even when we, the offended, are backed by our "two witnesses"? That is when we must involve "the church." (Matthew 18:17) Staff Islands and Offenses Related Topics: Appropriate Judgment | Dealing with Offenses | Diplomacy | Gossip | Judgment | Legal weight of two witnesses | Offenses, Dealing with | Two Witnesses