A 22-year-old man has died after being shot in Londonderry earlier this week.
Darren Thompson died of his injuries
Darren Thompson, from Harkness Gardens, was shot in the head in the Waterside area of the city on Wednesday morning.
He was found lying at the roadside in Woodburn Park with a bullet wound in the head.
It is believed he was attacked as he walked to work.
Mr Thompson was in a critical condition at Altnagelvin hospital, but died of his injuries at about 1400 BST on Friday.
He is survived by his parents, two brothers aged 15 and 18 and two sisters aged 22 and eight.
Two men and a woman are still being questioned.
Police said they were aware that some people were shielding those responsible for Mr Thompson's killing and said more searches and arrests would take place.
Chief Superintendent Patrick Steele said the murder inquiry was progressing.
"The investigation is progressing at a pace: we have made a large number of arrests, we have carried out a number of searches and recovered some terrorist weaponry," he said.
Police said on Friday that they believed the gunman made off on foot through an alleyway towards the loyalist Lincoln Courts estate.
A group is to be set up to help ease tensions in the Waterside following the fatal shooting of Mr Thompson.
After the shooting, a number of items - which had been set on fire - were found in the Lincoln Courts estate.
The Church of Ireland Bishop of Derry and Raphoe added his voice to appeals for calm and restraint following the murder.
Speaking on Saturday, the Right Reverend Ken Good said the murder was an outrage, but urged that there should no retaliation.
"Darren's tragic death has brought untold anguish and agony to his broken-hearted family," he said.
"In their grief, Darren's parents add their voices to mine in urging that any thought of retaliation for his death must not be even considered."
On Friday, the estate was at the centre of a security alert after suspicious objects were uncovered during a search.
Police said the items found included coffee jar bombs, blast bombs, incendiary devices and pipes suitable for manufacturing pipe bombs.
The items were discovered in a garden shed at a house in the estate.
Army bomb disposal experts are at the scene and residents were moved from a number of houses to a local community hall.
DUP Assembly member William Hay said about 12 families had to move from their homes in Lincoln Courts as Army bomb experts examined the scene.
"People are annoyed, angry and upset that this type of violence has been visited on them," Mr Hay said.
He added that concerned people within the community met police on Thursday.
"There is a great lot of fear within the community," he said.
"It is important to get this group so that they can relay the deep concerns of people to the police."