I've witnessed a crime, how can I handle this situation safely?

First of all - are you in a safe environment at the moment, or can you get you a safe environment? You can report crime anonymously in the UK both to the police on 101 in non emergency situations, or 999 in emergencies - or using Crimestoppers, who will pass on the information you give to the police. Please bear in mind that everyone copes with witnessing events differently, and what one person may 'bounce back' from may have a long lasting effect on another. You can be traumatised by, if not fully experience the effects of PTSD, and not be the direct victim of a crime, but a witness to it. Remember that most people who aren't involved in criminal justice (or emergency services) go through their daily lives not expecting to see criminal activity, or people at their worst, or just horrific events. Be aware of the signs of shock (clammy feeling skin, anxious, panic attack like feelings and shallow breathing). Also be aware of adrenaline dump after witnessing/being involved in these situations, which in turn can aggravate the risk of going into shock. In short, remember the safety of yourself and those around you. There are professionals who are highly trained in tactics to deal with situations that arise, some that are particularly heinous. Always remember your safety.

The safest thing to do once witnessing a crime is to call the emergency services. Then have a hot beverage and then afterwards, to talk to someone about the crime.

Do not interfere during the crime it is very dangerous, you can only call Emergency number to report to the authority. And when given your report do not add or remove any information, then your mind will be at peace.

Make sure you get to a safe place. Then contact the authorities I have found that seemed to work out okay when I experienced a crime happen in front of me.

If someone has been hurt and is in definite need of assistance, then giving them first aid if you can and calling an abulance/medical assistance is highly recommended. The wisest thing might be to make sure you are safe. Remove yourself to a safe location where you can first and foremost, calm down. If you've witnessed a crime, you'll be upset, to say the least, and depending on the crime. Once you are stable and feel safe, the option is: a) go home and try to forget, b) contact the authorities, and definitely a lawyer, just to be covered.

Write down everything you remember so as not to forget it. Then report it to the police at a moment you can where you yourself are safe from harm

Depending on the crime that was witnessed always make sure that you are in a safe place and safe location. Try not to bring attention to yourself and try not to be a hero in the situation. When you feel you are safe enough to do so get out of the area as quickly as possible and find someone whom you trust. If this was a very serious crime you may want to consider calling your local police or 911 but always making sure that your safe to do so.

Instead of discussing the situation with someone face-to-face, you can always submit a tip anonymously. I know for a fact in Ontario, we have this hotline called CrimeStoppers. See if there is anything such as this in your area! :)

The best thing to do for everyone's safety (including your own) is to make an anonymous report to the police regarding what you have seen and heard.

call the police and wait for a response and tell them everything u seen then let them deal with it