“Forensic science” means applying scientific methods and processes to solving crimes. Forensic science has become an integral part of many criminal cases and convictions. The extraordinary innovations and advancements in forensic science have allowed it to become a highly developed science that involves a number of disciplines. The field of forensic science draws from a number of scientific branches, including physics, chemistry, and biology, with its focus being on the recognition,identification, and evaluation of physical evidence. These scientific experts use microscopic examining techniques, complex instruments, mathematical principles, scientific principles, and reference literature to analyze evidence as to identify both class and individual characteristics. In the past decade, they have started using laser scanners, drones and photogrammetry to obtain 3D point clouds of accidents or crime scenes. Reconstruction of an accident scene on a highway using drones involves data acquisition time of only 10-20 minutes and can be performed without shutting down traffic. The majority of forensic scientists perform their jobs within the confines of the forensic laboratory or morgue; their work may also take them outside of the laboratory and to the crime scenes, where they observe the scene and collect evidence. Forensic scientists may work for local, state and federal law enforcement agencies and government, private laboratories, and hospitals. They may also serve as independent forensic science consultants.

The appearance of smartphones has changed people’s life to a large degree. Not only can people use them to make and receive phone calls, they can 46 use them to surf on the Internet, send and receive emails, communicate with each other through video and make new friends. They have helped make human contact become easier and more 47 than before. Besides helping people to connect 48 each other, smartphones allow people to have fun. People can watch videos and movies online as well as play many different online games either with themselves or with others. Using the camera function 49 by smartphones, people can take pictures of themselves, their family and friends and even things that interest them. Now smartphones have also been used as a kind of credit card. 50 , people can use them to pay for their grocery shopping without taking the money with them.