The Justice Minister today met the colleagues of Detective Garda Adrian Donohoe, including Detective Joe Ryan who was with him when he was shot dead by a gang at a Credit Union near Dundalk on Friday.

Minister Alan Shatter paid tribute to Garda Ryan for his courage, and said there was a mood of determination among gardai that Detective Donohoe's killers will be brought to justice.

Meanwhile, a steady flow of people have been arriving at Dublin's Mansion House to sign a book of condolence in memory of Detective Garda Adrian Donohoe. 

It’s open until 5pm this evening and will open at 10am tomorrow and Wednesday. 

Dublin's Lord Mayor Naoise O'Muiri said he decided to open the book at 2pm today to give people the chance to express their sympathies to the deceased garda's family.

The Lord Mayor was the first to sign the book of condolences.

“So saddened by the loss of Adrian. He died serving his community and country. We are here to support you.”

Assistant Garda Commissioner, John Twomey was second to sign the book.

“Very sad times for the family of Detective Garda Donohoe and our thoughts and prayers are with his family.

The rain did not deter people from gathering to pay their respects.

Dublin woman Anne Gibney said people were stunned and that Adrian’s death didn't quite register with them at first. 

Niamh Gallagher of Women4Election said she was shocked and devastated that violence has gone to the level of attacking the gardai and was in disbelief that this could happen.