[14] The Armed Support Unit arrived at the scene after Horkan pressed his panic button on his radio for emergency backup prior to the shooting.

A small marquee was set up on the street where the incident occurred and tributes were led by local Fianna Fáil councillor Paschal Fitzmaurice.

[24] Due to the COVID-19 pandemic in the Republic of Ireland, social distancing protocols meant the numbers in the church were limited to Horkan's immediate family along with Garda Commissioner Drew Harris and the Minister for Justice and Equality Charles Flanagan.

At Áras an Uachtaráin, the president attended a ringing of the Peace Bell and raised the Irish flag at half-mast as a mark of respect to Horkan.

[28][29] On 5 September, Minister for Justice Helen McEntee honoured and reflected on the loss of Horkan as she marked National Services Day 2020.

[37] In August 2020, it was reported that the extent of the investigation involved 200 statements, 250 exhibits and 70 segments of CCTV footage, while gardaí made inquiries with a witness in Australia.

[38] On 6 November 2020, five months after the shooting, further charges were considered against Silver as he was deemed medically unfit to attend court for the eleventh time and remained at the Central Mental Hospital.

[49] On 15 March 2023, Silver was found guilty of the capital murder of Detective Garda Horkan after two trials at the Central Criminal Court.