You must always bear in mind that the government has the burden of proving you guilty beyond a reasonable doubt. You don't have to do anything. Obviously, if the government has "no evidence" against your friend, they can charge him with a crime. But, frequently prosecutors will act as if they have "something" even though they are required by law to turn all exculpatory evidence over to you. This is called discovery. You should see an attorney because "burglary of an (inhabited) dwelling and false imprisonment or and assault and battery are very serious offenses and could result in going to jail or prison.  And if it's a felony, the chances are there will be a bond you have to post to get out of jail.  But on the brighter side; prosecutors frequently charge more crimes than they can prove in order to force you into a "plea bargain."  I hope this information is helpful to you. See an attorney; this is nothing to do by yourself and do not talk to the cops about the case under any circumstances.  It cannot help you.