When laws are broken the consequence of more serious crimes can result in a custodial sentance leading to imprisonment. The result of some less severe cases can still result in community service and others in hefty fines. Although for the majority of first time offenders a suspended sentance and a warning are often all that happens, you would have still earned yourself a criminal record. However you don't always have to be the person that directly or actively committed a crime to get punished for it, if you are implemented in any way to the planning of, aiding of or covering up of a crime, you are leaving yourself wide open to the chance of a conviction.
In the eyes of the law you are at least partly guilty of and in some way responsible for the criminal act, even if it wasn't actually you that did it. The justice system works in such a way that all criminal acts must be investigated and the perpetrators punished. If you are aware of any criminal activity that is either being planned and is possibly going to happen, or any criminal activity that is in progress and happening now or has already been committed and you are aware of it, then it is your moral duty as a citizen to report what you know to the police.
The job of the police is to gather all the available evidence of the crime and to produce enough proof to ensure a conviction, but also to remain unbiased and to enable a fair trial. If you think you or a friend might be punishable by law because you have or indeed they have been associated in some way to a criminal act, law braking activity or the obstruction of justice being fulfilled, you may be worried or worried for your friend and wondering where you stand legally.
If you have deliberately instigated or recruited people in the the committing of a criminal offense and substantial proof of this can be obtained and given as evidence in a court of law you will be classed as an accessory and duly punished according to the severity of the crime.
Similarly if you have actively and intentionally lied about the whereabouts of a person that is suspected of or has been charged of a criminal activity after it has been committed you are also liable to be charged with the offense of being an accessory.
The principle offender is someone who has directly committed the crime and as such does pay a heavier price for the trouble they have caused, however even though the courts do make distinctions between the principle perpetrator and the person or people who aided and abetted them, accessories can still be given a heavy sentance for their involvement depending on the seriousness of the crime and the attitude of the judge passing the sentance.
Less severe penalties go to those involved after a crime where as anyone being the instigators of crimes are as likely to get the same as the people who committed it. Current legislation tends to dictate that accessories before the fact are charged and tried the same as the perpetrators. It is against the law to help a criminal to escape justice and is also punishable by law.
However if you help shelter a criminal, without knowing that they were wanted by the police or unaware of what they had done, you are not classed as an accessory because you were simply oblivious to the fact. Similarly if you were forced physically or threatened to keep quite or to cover something up, this will go in your favor in a court of law as it was done against your will, you will therefore not be classed as an accessory or for willingly aiding or abetting.