committed crime overseas

In the UK if you commit a crime you will be listed as a wanted person. As far as I know there is no random ID check in the UK so unless you get involved in something to do with the police, like a car accident or a drunken bar fight, the chances of you being caught is small. But while putting you on a wanted list, the police would also put you on a watch list. The Watch List is an alert to all UK immigration officers at airport, inter-continental train stations (eg. Eurotunnel), and ports. When you try to leave the country you will be caught.
If the police found out that you have already left the country, your name and passport number will be put on watch lists of all other countries' immigration service - no matter how big or small the crime is. The difference here is that for countries that has a repatriation agreement with the UK, you will be apprehended when you enter that country. Then you will be deported back to the UK. For countries that has no repatriation agreement with the UK, the police will secretly keep an eye on you, if possible, and inform the UK authorities when you leave that country. This is a very passive method to try to catch you.
However, for serious crimes such as murder, terrorism, large-scale commercial fraud, rape etc., the UK police will take positive action to try to catch you by notifying the Interpol, besides putting you on watch lists. The Interpol will actively seek you out and try to catch you in whatever country you are in.

In the UK if you commit a crime you will be listed as a wanted person. As far as I know there is no random ID check in the UK so unless you get involved in something to do with the police, like a car accident or a drunken bar fight, the chances of you being caught is small. But while putting you on a wanted list, the police would also put you on a watch list. The Watch List is an alert to all UK immigration officers at airport, inter-continental train stations (eg. Eurotunnel), and ports. When you try to leave the country you will be caught.

If the police found out that you have already left the country, your name and passport number will be put on watch lists of all other countries' immigration service - no matter how big or small the crime is. The difference here is that for countries that has a repatriation agreement with the UK, you will be apprehended when you enter that country. Then you will be deported back to the UK. For countries that has no repatriation agreement with the UK, the police will secretly keep an eye on you, if possible, and inform the UK authorities when you leave that country. This is a very passive method to try to catch you.

However, for serious crimes such as murder, terrorism, large-scale commercial fraud, rape etc., the UK police will take positive action to try to catch you by notifying the Interpol, besides putting you on watch lists. The Interpol will actively seek you out and try to catch you in whatever country you are in.

希望幫到你啦！

If this is a very big issue, they will find you even you are overseas. Otherwise, when you enter to UK again, the UK custom will arrest you right away.