Yes, was it 16 years, that is a long sentence and reflects the severity of the abuse he was convicted of.
I've read that his daughter's first complaint was at age 13, when she said the police were more concerned about the links to Uncle gerry Adams and the potential impact on the peace process. Uncle Gerry was also approached by his niece, and spoke to his brother Liam about the allegations, who (surprise) denied them. The news reports talk of rapes and indecent assaults between the ages of 4 and 9. The first rape took place when the girl's mother was in hospital, giving birth.
It seems the young woman went back to the Police to re-state her allegations after finding that her father was involved in Youth Work and realising the significant implications for other young people. Gerry Adams is alleged to have known his brother was involved in youth work.
I've read that Liam and Gerry Adams' father was physically, emotionally and sexually abusive within his family.
A very courageous young woman, who seems to have had good support from her mother once she was informed of the abuse.