13. According to the passage, DNA should be collected from a crime scene because
(A) it is better than fingerprints.
(B) there is DNA left at every crime scene.
(C) it can be used to eliminate potential suspects.
(D) DNA is a new investigative tool.

    DNA is a powerful investigative tool because no two people have the same DNA. The only exception除外 scientists have found to this is identical相同、相似 twins. The sequence順序, 一連串, or order, of the DNA building blocks積木、基礎材料 is different in particular regions of the cell, making each person’s DNA unique. Because of this, DNA evidence collected at the scene戲劇／電影, 場景 of a crime can link a suspect to the crime or can eliminate someone from suspicion. DNA is similar to fingerprints, but has been considered more accurate for the past decade. DNA can also link evidence to a victim by using DNA of relatives if the victim’s body cannot be found. For example, if technicians have a biological sample from the victim, such as a bloodstain found at the crime scene, the DNA taken from that bloodstain can be compared with DNA from the victim’s biological relatives to determine whether the bloodstain came from that particular victim. When a DNA profile簡短的描述, 傳略；人物簡介 developed from evidence at one crime scene is compared with a DNA profile developed from evidence found at another crime scene, the crimes can be linked to each other or to the same suspect, making it possible to link crimes committed at a distance from one another. 

    Although many forensic法醫 scientists had begun to think of DNA as a miracle identifier, in 2009, scientists for the first time found that it was possible to  fabricate捏造，虛構；偽造 DNA evidence from a person other than the donor捐贈者 of the blood or the saliva口水. This means that someone could plant another person’s DNA at a crime scene, causing the person whose DNA was found to be considered a prime首要，主要 suspect in a case. While this does not mean that DNA evidence will no longer be important, it reinforces加固 that solving crimes must continue to rely on more than science to find a guilty party社交聚會、政黨.