Sybrina Fulton, mother of Trayvon Martin, has testified in court in the case against George Zimmerman. Zimmerman is accused of the February 26, 2012 shooting of Martin after having called 911 to report a suspicious figure in his gated community (Zimmerman, a neighborhood watch captain, had made similar calls several times over the previous six months).

When asked by Prosecutor Bernie de la Rionda whether she had any children, Fulton replied, “My youngest son is Trayvon Benjamin Martin. He’s in heaven.”

After describing her son’s tattoos—one of which had the names of his grandmother and great-grandmother, the other Fulton’s name—De la Rionda played an audio recording of a 911 call placed by a neighbor who witnessed Zimmerman and Martin’s struggle. The recording featured screams that Fulton testified to be her son’s, followed by a gunshot.

On cross-examination, defense attorney Mark O’Mara suggested that Fulton wanted the screams to be those of her son rather than Zimmerman, a claim Fulton rejected.

Martin’s brother, Jaharvis Fulton, also took the stand, claiming that the voice was Trayvon’s. This testimony forced Jaharvis to recant a previous report that he wasn’t sure whose voice it was. “How do I explain?” he said, “I guess I didn’t want to believe it was him. . . . I guess listening to it was clouded by shock and denial and sadness.”

Martin’s father, Tracy Martin, had previously told authorities that the voice in the recording was not Trayvon’s.

An FBI audio expert testified that technology couldn’t definitively clarify whose voice it was, but a close relative may be able to tell. Even so, he warned, bias on the part of the listener could influence what that individual heard.

Zimmerman is charged with second degree murder. The case has aroused racial tensions nationwide, as Martin was African-American and Zimmerman’s willingness to pursue Martin has been suggested to have been racially motivated. The Martin incident was the fifth time in seven months that Zimmerman had called 911 to report a suspicious person in his community. In all five instances, the person Zimmerman identified as suspcious was an African-American male.

If convicted, Zimmerman could face 25 years to life in prison.