Short answers, pulled from the story.
The first written account of using science to solve a crime appeared in 1248 in the courtrooms of Song dynasty China. Song Ci published the book known as Washing Away of Wrongs which introduced regulations for autopsy reports and methods to protect evidence.
Forensic DNA analysis was first used in 1984 and was developed by Sir Alec Jeffreys. He realized that variation in the genetic sequence could be used to identify individuals and to tell individuals apart from one another.
A method for detecting arsenious oxide in corpses was devised in 1773 by the Swedish chemist Carl Wilhelm Scheele. James Marsh was the first to apply this new science to the art of forensics and developed the Marsh test in 1836.
Juan Vucetich set up the world's first fingerprint bureau in 1892 after studying Galton's pattern types. In that same year Francisca Rojas of Necochea was found in a house with neck injuries and her prints were matched to a bloody thumb mark on a door.
Frances Glessner Lee is known as the mother of forensic science and was instrumental in the development of forensic science in the US. She lobbied to have coroners replaced by medical professionals and created the Nutshell Studies of Unexplained Death to train investigators.
According to the Innocence Project and the US Department of Justice, forensic science has contributed to about 39 percent to 46 percent of wrongful convictions. The Innocence Project database of DNA exonerations shows that many wrongful convictions contained forensic science errors.