A £10,000 reward is on offer for anyone who provides information leading to the conviction of those responsible for Lyra McKee's murder.
Ms McKee was shot dead by indiscriminate fire in Derry last week as she observed clashes between police and New IRA dissidents on the Creggan estate.
Launching the reward for information, a spokesman for Crimestoppers, said it could “make all the difference in helping Lyra’s loved ones and the wider community have the answers they deserve”.
“This murder has sent shockwaves through the local community and across Northern Ireland. Indeed it has attracted global condemnation,” Crimestoppers said.
“Ms McKee was merely doing her job as a freelance journalist.
“We know that this has affected all parts of the community and we urge anyone who has information about those who are responsible to come forward.”
The 29-year-old's funeral was held in Belfast on Wednesday in which thousands turned out to pay respects to the murdered journalist.
Prime Minister Theresa May stood alongside her Irish counterpart, Taoiseach Leo Varadkar and Sinn Finn leader Mary Lou McDonald sat next to DUP chief Arlene Foster inside St Anne's Cathedral.
Fr Martin Magill, the priest leading the service, received a standing ovation when he asked why it took the death of a 29-year-old woman to unite their parties.
Mourners said they hoped pleas for action would not fall on deaf ears.
Mrs May said afterwards: “We must do our utmost to ensure that that does not happen.”
The 100-year-old cathedral in the heart of Belfast was packed for the funeral, where there were tears and laughter for Ms McKee.
The congregation was led by Ms McKee’s partner, aged 35, her mother Joan McKee, 68, brothers Gary and David and sisters Joan, Nichola and Mary.
Her family earlier paid tribute to a “gentle, innocent soul” whose “desire to bring people together made her totally apolitical”.
Lyra’s friends filled the pews wearing homemade #TeamLyra t-shirts, with Harry Potter-esque crests on the front.
The New IRA has claimed it was behind Ms McKee's murder and the group offered "full and sincere apologies" to her friends and family in a statement.
An amalgam of armed groups opposed to the peace process, the New IRA recently claimed responsibility for parcel bombs sent to London and Glasgow in March.
Police believe the violence in Derry was orchestrated in response to an earlier search by officers aimed at averting imminent trouble associated with the anniversary of the Easter Rising.
Crimestoppers takes calls confidentially via a telephone or using an anonymous online form.
The spokesman said: “By contacting Crimestoppers, you stay 100% anonymous. Always.
“You can pass on what you know, safe in the knowledge that you’re doing the right thing. No-one will ever know you contacted us and you may also be entitled to a reward.”
The number to call is 0800 555 111 or the anonymous online form is available at Crimestoppers-uk.org.
The reward will expire on July 24.