The home secretary said the government will look at reinforcing the witness protection programme to encourage communities to share information.
Visibly upset, Jacqui Smith was talking about the murder of 11-year-old Rhys Jones, hours before Liverpool police said they were disappointed by the lack of public help in finding his killer.
Speaking to Channel 4 News, she said she was "willing to consider anything" that would encourage people to give information after a serious crime, stressing the police needed the community's help to identify suspects and gather information.
Ms Smith said: "One of the issues, of course, as the Chief Constable made clear in Liverpool, is that we need people in local communities to be willing to firstly stand up against gun crime, but also to give information to the police [and] to be willing to come forward.
"That doesn't always mean that they will need to act as witnesses but we need people to feel confident about that."
She added: "I am willing to consider anything that will help us to get the information to put people away."
Later, Merseyside police launched a fresh appeal for information from residents in the Croxteth area of Liverpool.
Patricia Gallan, assistant chief constable, admitted they were "disappointed" by the public response.
She said: "We need to get this killer off the street. Within this community people know who is responsible for this crime."
Merseyside Police have now set up a special telephone number which young people can text anonymously.
Earlier today, former home secretary David Blunkett said more needed to be done to reassure witnesses they would be protected.
He told BBC Radio 4's Today programme: "In some of these communities, particularly where there are gangs, there will be youngsters who know who did it.
"There will be parents whose youngsters look frightened and worried.
"If only we could get them to share their knowledge and be protected in circumstances where they know that their fellow teenagers are carrying guns then we might get them to be able to collaborate and come forward."
Ms Smith also said she had been talking with the prime minister on how to combat the availability of guns.