JACKSONVILLE, Fla. -

Tuesday marks four months since 22-year-old Amber Bass was shot and killed in her own driveway.

No one has been arrested in the case.

The shooting happened at the family home on Springtree Road on the Westside, near the intersection of Foreaker and Old Middleburg roads.

Bass' friends held up signs Tuesday in front of the Duval County Courthouse, hoping it could lead to a tip that could crack open the case.

Pete and Susan Singer were two of those family friends.

"I just continually think about her every day," said Pete, who spent his birthday Tuesday seeking justice for Bass. "You know, whenever I can go out and do something for her, go out and help other families -- I will always want to do that."

"It hurts like the very first day still," Susan said. "I'm fighting back tears as we speak. I can't tell you how much she's missed."

The Singers say the pain of not knowing is hard enough. They say Bass' family recently got the news from detectives that all leads in the case had dried up and that any new leads must come from the community.

"That was such a kick in the gut," Pete said. "You don't want to know that nobody's looking anymore."

Even though Bass' case is especially close to their hearts, the Singers don't want the dozens of other unsolved cases to be forgotten. Cases like that of Michael Siegrist, who was killed trying to intervene in a robbery at a bus stop in July. And 83-year-old Robert Levy, who was found killed in his burning home in Englewood in June. And Thomas Michael Kirby, a Jacksonville Transportation Authority bus driver whose body was found in front of an abandoned home.

Channel 4 crime analyst Ken Jefferson said it's important as ever to bring justice to all grieving families.

"Someone knows something and they're just not divulging this information now," he said. "You can imagine the wit's end that the families are feeling now because there's been no progress."

The Jacksonville Sheriff's Office released this statement Tuesday:

"This is still an active investigation. Detectives have not stopped working this case. As always we are looking for tips from the community. Anyone with any information is asked to please come forward. The purse the victim had that night is still being sought."

Anyone with any information about the unsolved killings is asked to call Crime Stoppers at 866-845-TIPS.