What are the amazing reasoning bridges?

Song Ci, a criminal prosecutor, told a story about drying a sickle: a man was killed and injured in more than ten places, all of which were sickle injuries. Song ci found that the property was intact and the clothes were all there, and concluded that it was a vendetta. After investigation and interview, Song Ci locked the suspect. He asked nearby residents to hand over all their sickles and put them on the ground respectively. There are always seventy or eighty sickles. It was midsummer, and flies gathered on one of the sickles, unable to stay. The inspector found the owner of the sickle. Song Ci said that flies are bloodthirsty. This sickle still has blood gas after killing people, which leads to the gathering of flies, while other sickles have no such situation. It can be inferred that the owner of this sickle has killed people. In front of the evidence, the murderer bowed his head and confessed. Hardly had Harry arrived in Chun 'an when he discovered a mystery. Although the murderer made an oath, his confession was like a confession made under duress. The murderer's name is Shao Shizhong, and he has been at odds with the victim Hu Shengzu. Half a month ago, Hu Shengzu went to the mountain to see his land, and Shao Shi killed him with a stick. Hu Shengzu's two brothers, Hu Rong Sheng and Hu Shengyou, found the body and the murder weapon and reported to the county government two days later. Harry ordered an autopsy. He shaved the hair off the victim's wound. I took another disk and kept scraping on the bone of the wound. He pried open the mouth of the body again, and then let people take off the clothes of the body for a long time, and ordered to go back to the official court to hear the case. Harry asked Hu Shengzu's brother to repeat the case and asked him if your brother was seriously ill before the accident. Hu thought about it and said that his brother was really ill. Harry then asked, then why did you report it two days later? Nonsense, it was two days before he went up the mountain to find his brother's body. Harry suddenly patted the gavel and said, I scraped the wound several times with a magnetic sheet, and after scraping off the blood on the surface, the bones below were not even red. And the meat around the wound is very black, which is the color after the blood stops flowing. There are indications that the blood on the body, including wounds, seams and sticks, was painted later, and the heavy blow to the head of the body was only played after death and blood coagulation! It turned out that Hu Shengzu died of illness, but two days after his death, his two brothers planned to use his brother's body to frame Shao Shizhong.