The Gospels have been much maligned as being copied one from another, not from independent witnesses (for Matthew, Mark and Luke) and that they were written a long time after the events, hence lack eyewitness statements. The Wikipedia page on this notes:
Although some claim that all four canonical gospels meet the five criteria for historical reliability, others say that little in the gospels is considered to be historically reliable. … Most scholars hold to the two-source hypothesis which claims that the Gospel of Mark was written first. According to the hypothesis, the authors of the Gospel of Matthew and the Gospel of Luke then used the Gospel of Mark and the hypothetical Q document, in addition to some other sources, to write their individual gospels. These three gospels are called the Synoptic gospels since they are all very similar.1
Dr Floyd Nolen Jones responds to claims like these in an article2 “The Gospel Colophons.” In the following I reproduce it in full.