The garda chief superintendent in Louth, Christy Mangan, has said the garda's elite Emergency Response Unit (ERU) has never let him down and will be there at a moment's notice.
Speaking on LMFM radio in Drogheda, Co Louth, where a drugs feud has resulted in three murders, he also encouraged everybody to support this weekend's Standing Together march and rally.
Chief Supt Mangan said detective units from three garda divisions were involved in the investigation into last week's murder of Drogheda teenager Keane Mulready-Woods.
He confirmed gardai believe he was killed in the town, and he says not everybody who has information about what happened has come forward yet.
He told LMFM presenter Michael Reade that the area Mulready-Woods (17) was last seen in, Dominic's Bridge, was a busy area and some people had contacted gardai.
However, he also said: "I certainly would appeal to other people who are certainly in possession of information in relation to where Keane went, who he met and ultimately what happened to him and where. They are the important things we are trying to establish."
He said people with information who do not come forward, carry a huge responsibility.
Gardai know from other investigations into horrific crimes that for people with information who do not come forward, "they will have to live with that for a long time, maybe for the rest of their lives".
He said Mulready-Woods's family was endeavouring to plan for his funeral but some of his remains were still missing.
Asked about reported concerns about a lack of resources hampering the effectiveness of the ERU, he said: "I have never ever had any difficulty securing the services of the ERU, they have been really, really good.
"They will be here at a moment's notice for me, whether it be three o'clock in the day or three in the morning, they have been here.
"When they come here they are suited and booted and well able to do the job that I ask them to do on a regular basis.
"I have made a request at two o'clock in the morning and I have got them out and they have turned up and done a lot of good work for me."
He appealed to people to take part in a march and rally that has been organised for this Saturday afternoon.
"I would encourage everybody, and I mean everybody, in Drogheda to come in and show to the people of Ireland that they are standing up for their town," he said.
"Through fear must come courage. We have to have courage to stand together to take them on.
"We will do it. I have no doubt we will do it and on Saturday I would encourage everybody who is able to get into town.
"It will be a well-planned meeting where people can come in and express their opinions in relation to the whole debacle and we will be there to make sure they are safe. We will have a good policing plan in place."
The Mayor of Drogheda, Paul Bell, said: "It's time to take back our town from the criminality which has caused so much misery and anxiety to all of us.
"As mayor I seek your support in the fightback against drug crime and violence. We can take the step together by attending the Standing Together march and rally on Saturday."