A review has found that there was not enough evidence to justify prosecuting the Sinn Féin leader Gerry Adams for allegedly withholding evidence about his brother, Liam Adams.
It comes after his Liam Adams was convicted of raping and abusing his daughter in the 1970s.
Liam Adams (59) from west Belfast was jailed for 16 years in 2013 for attacking her, and lost his appeal against his conviction last month.
Áine Dahlstrom waived her right to anonymity in order to seek justice.
Northern Ireland's Attorney-General says a prosecution should only be taken if there is enough evidence to ensure a reasonable prospect of conviction, and says this was not the case for Gerry Adams.
However the report by John Larkin also says prosecutors reached their decision on whether to prosecute Deputy Adams prematurely because there were some indications that he may have been aware of his brother's abuse.
He says it would have been necessary to interview Deputy Adams under caution to fully discover the extent of his knowledge, before deciding whether he should be prosecuted.
The report also states that Ms Dahlstrom did not want Gerry Adams to be prosecuted - and that prosecuting him may create an environment where witnesses were unwilling to come forward because they could be prosecuted for not doing so sooner.
Deputy Adams has welcomed the findings and says he did not commit any offence.
Pamela Atchinson from the Public Prosecution Service says that is now the end of the matter.