when do you risk revenge

oh, OK.  I thought it was revenge going the other way.

I would think the police would have protections for witnesses and accusers.

Is the danger completely gone if you dont come forward?  Is there a good chance this crime(s) happen again if you just let bygones be bygones?  

Follow Brians advice ...

brianlux said:

I would go to the police, tell them in very general terms what is going on and tell them that you are concerned about giving particulars because doing so might cause reprisal from the perpetrators and ask them for advice on how to stay out of harms way.  I don't know if that's the best advice, but that's the best I can come up with.

Whatever you decide, I hope it turns out well for you and yours, last exit.

Yeah, I agree that you at least start by calling the police on the phone and tell them your situation without naming any names and find out what they could do to protect you and/or your family member. Doing nothing could just hold you in a position where you're at the mercy of a gang forever - if she doesn't go to the police, she is just a person who hasn't gone to the police YET. Gangs tend to like to get rid of witnesses, don't they?
But this is a bad situation either way man. You kind of have to accept that you're maybe damned if you do, and for sure you're damned if you don't. I would personally take the risk of contacting police and having revenge exact on me over living under the thumb of a gang. The situation has already gone past the point where your family member is really going to have a good, clean, risk-free way of getting out of it.
And then there is the final factor: what's the right thing to do? Maybe think about the actual victim(s) of this serious crime when considering that.

lastexitlondon said:

they have taken things from her house for DNA . but she is reluctant.  but I want to get these people  in prison asap. but they have a big circle. gypsys  and gangs of bad people . I know she should not have mixed with them . but it's too late. 

Well, I guess you hit the nail on the head. It's too late. She should cooperate. Dyer there has a point, but she's only 17 - she may need extra guidance and real help making decisions on this. If the way you're describing the risk is accurate, I'm going to guess that the fact that the police have already been to the house and collected evidence is known to them anyhow, so it maybe couldn't get much worse at this point... But seriously, if she is going to actually testify against them in court, then the cops ought to be providing real protection for her, if there is any concern that they'd go after a witness who's testifying.... If she actually has useful info for the prosecution, wouldn't she be compelled to testify anyhow? Are the cops really oblivious to the fact that she knows something if they've swabbed her house for DNA samples?

lastexitlondon said:

the cops know what's happened  but they can keep the evidence  for 6 years. they can't prosecute without het statement  and will to report the crime. so I guess I will wait and see what she wants. 

Hard to say without being closer to all this but it sounds to me like if the cops are asking for her statement maybe she could ask for some protection if she agrees to gives it.  But don't make demands.  Cops want to be in charge.  They are generally more helpful when they are in control of a situation.  Get them on her side.  And maybe give the statement and find a safe place to stay for a while, if possible.