Shrinking violets need not apply. There are two types of danger that you should anticipate: expected and unexpected. Expected dangerous scenarios include process serving, marital investigations, surveillance, undercover investigation, criminal investigation, and bodyguard work. Unexpected danger can occur when someone seeks revenge, working in a dangerous part of town, or when a client or case turns violent.
The death of private detective, Daniel Morgan, is a good example of expected/unexpected danger. Morgan was a private detective until he was killed in 1987. He was working on a case that would expose the corrupt relationship between the Metropolitan Police and the Crown Prosecution Service in south London. Apparently, someone did not appreciate his moxie and killed him with an axe. The case is still open. Mysteriously, the police have never found his murderers. We're sure it has nothing to do with them being biased. Surely, Morgan knew the physical danger he was in. It’s also probable that he didn't see the axe coming. When you conduct a dangerous investigation, it is important to remember that even when you clock out for the day the danger doesn't end. Criminals don't clock out. Private detectives should take preventative steps during investigations, such as making sure they don't have a tail when going home. You may think it would be a good idea to carry a gun. Wrong.
For the most part, private detectives do not carry guns. You don't become an arm of the law when you get a license. Basically, your job is to collect evidence for someone else. Knowing that you play no part in enforcing a type of punishment for the perpetrator helps prevent emotional involvement. Also, toting a gun could lead to corruption. Don't be that rogue detective who threatens people. That is not being a good detective. It's being a criminal.