Final preparations are taking place in Charlestown, for the State funeral of Detective Garda Colm Horkan.
Mass is due to get underway at midday.
The remains of Detective Garda Colm Horkan are to be brought from his family home to St James' Church in Charlestown for mass at noon.
It will coincide with a minutes silence at every Garda Stations across the country - led by the ringing of the Peace Bell by President Michael D Higgins at Aras an Uachtarain.
Despite the rain, huge crowds are expected to line the streets of the Mayo town to pay their respects to the officer who was killed on Wednesday night while on duty in Castlerea County Roscommon.
Following the State funeral, which will be streamed by An Garda Siochana and broadcast live on Midwest Radio, Detective Garda Horkan's remains will be brought to the nearby cemetery for burial.