When Soulja Slim (née James Tapp) was murdered on the front lawn of a New Orleans duplex in 2003, there was both an outpouring of sympathy and outrage on the slain rapper’s behalf. Family members, fans and local residents also hoped the killer would be quickly identified and sentenced. Four years later, the man who shot Soulja Slim multiple times remains free, and authorities believe he has committed or assisted in at least three other murders.

Garelle Smith was arrested in connection with the murder of Soulja Slim in 2003, and he was also charged for his role in the murder of Mandell Duplesis in 2007. The New Orleans Parish District Attorney‘s office says Smith remains free because they lost track of witnesses in both cases.

“[Smith’s] arrest record with the New Orleans Police Department started at the age of 10 when he was a juvenile,” says Rafael Goyeneche, who serves as head of the Metropolitan Crime Commission.

Smith was arrested again in 2007 for his alleged role in a murder in New Orleans’ St. Bernard Housing Projects. Despite being a member of the D.A.’s Victim Assistance Program, the key witness against Smith mysteriously disappeared. District Attorney Eddie Jordan was again forced to drop the charges against Smith.

In April, Smith was arrested for his alleged connection in the death of Terry Brock. After other suspects were arrested, the D.A.’s office refused the case and another investigation led to Smith. Charges against Smith were once again dropped when a witness refused to testify.

“We depend on the community and witnesses in each case to pursue charges against defendants,” Bobby Freeman, head of the Violent Offender Unit, tells local CBS affiliate WWL-TV. “It hurts not only our case, but the community at-large, when witnesses refuse or are unable to come forward.”