Murder of Inga Maria has been on NI's conscience since 1988

The German teenager was aged 18 when she was killed in Co Antrim.

The riddle of her death has still not been solved and it will be an agonising story without any resolution until it is.

It is a particularly poignant aspect to her tragic fate that she came here on her own as the Troubles were receding and tourism was beginning to pick up.

Come to Northern Ireland, we told visitors. It is safe. The murder toll per capita is lower than in American cities, even when the political killings are counted.

And so it was a much safer place to visit than some US inner cities.

Inga Maria came as a backpacker with hope and expectations, but ended up in a shallow grave.

It is always reassuring to hear police talk in a way that suggests that they know roughly who the killer (s) was/were.

There are also thought to be other people who have been involved in covering it up.

Perhaps they will yet be caught by DNA evidence.

Or perhaps someone will come forward.

As the superintendent in charge of the case has said today, there might be people who have information which they are finding it hard to live with.

If so, we can only hope that they do the right thing before they die.

Living with such a burden must in itself be a form of living hell, that might even be worse than anything the criminal justice system will hand out.

Inga Maria’s father died without finding out what really happened to his murdered daughter.

Her mother is still alive.

Perhaps the 30th anniversary of the killing will finally see the case move forward.