I would use the word engineer.
Albert Einstein
A detailed answer to the question can be found in John Forge's book The Responsible Scientist.
The theme is that mankind may not be ready for the weapon that the scientist was making. the point that the visitor had to prove is shown by the scientists son, who is retarded, accepts a loaded revolver which is the same as mankind and the scientist's weapon.
He use Weapon with a stone
The head scientist of the Manhattan Project, this project was the development of the first U.S nuclear weapon.
If there is a hole in a person, it was probably a bullet. If there is a big cut or wound, then it may be a knife.
Dr.APJ Abdul Kalam made a nuclear weapon (missile) which was named as Agni
Danish scientist Niels Bohr said, 'The best weapon of a dictatorship is secrecy, but the best weapon of a democracy should be the weapon of openness.' Additionally, John F. Kennedy was quoted as saying, 'The very word 'secrecy' is repugnant in a free and open society.'
Some advantages are that you get respect from the law and you should feel 'happy' that you have solved a murder or what ever you are doing that field. Also... you can get to work out who did the murder, and how, what is the murder weapon, and if it was a gun or a long distance weapon where it came from. X
To the scientist, it was inconceivable that his invention might become a weapon. The explosion could have caused an inconceivable amount of damage to the residential area.
There could be more than one element vying for the most important in a story about a mad scientist stealing a secret weapon. Two could be the elements of surprise and suspense connected to how he gets away with it. Another element could be danger. This could keep the audience on the edge of their seats.
If you are asking a professional forensic scientist, then you could ask:Is it possible for you to tell what distance the victim was from the weapon when he/she was shot? Is it more likely for a bullet to go straight through the skull and out or does the bullet stay in the skull?