Word: Alleged, allegation

I am always struggling with these two words trying to understand what they mean when I see them on the telly.

Could anyone explain me how I can work out the meaning of them in the following contexts.

1- alleged evidence

2- past allegation

e.g

The Michael Jackson trial entered a potentially critical phase yesterday as prosecutors prepared to introduce evidence of past allegations of child sexual molestation involving the 46-year-old singer.

Thanks

Alleged:
stated but not proved
dictionary.reference.com/browse/alleged

Allegation:
statements affirming or denying certain matters of fact that you are prepared to prove
dictionary.reference.com/browse/allegation

In layman’s terms:

Alleged evidence is something the authorities have that may tie someone to a crime.

Past allegation is something the authorities have accused individual of doing in the past (but was not necessarily proven).