A grand jury will not look into the Trayvon Martin case, a special prosecutor said Monday, leaving the decision of whether to charge the teen's shooter in her hands alone and eliminating the possibility of a first-degree murder charge. That prosecutor, Angela Corey, said her decision had no bearing on whether she would file charges against George Zimmerman, the neighborhood watch volunteer who has said he shot the unarmed black teen in self-defense. Corey could still decide to charge him with a serious felony such as manslaughter which can carry a lengthy prison sentence if he is convicted. A grand jury had been set to meet Tuesday in Sanford, about 20 miles northeast of Orlando. Corey has long had a reputation for not using grand juries if it wasn't necessary. In Florida, only first-degree murder cases require the use of grand juries. Corey's decision means she doesn't have to rely on potentially unpredictable jurors, said David Hill, an Orlando criminal defense attorney. Let's give her the benefit of the doubt. Maybe she knows there isn't enough for first-degree murder but she wants to maintain control and charge him with something else," Hill said. What does she need a grand jury for? She cuts out the unpredictability of the grand jury. She goes where she feels she has more evidence. Corey took over the case last month after the prosecutor who normally handles cases out of Sanford recused himself. That prosecutor, Norm Wolfinger, had originally called for the case to be presented before a grand jury. "From the moment she was assigned, Ms. Corey noted she may not need a grand jury," said a statement from Corey's office. Prosecutors sometimes use grand juries to avoid the political fallout from controversial cases. But Corey was elected by voters more than 100 miles away in the Jacksonville area, so political problems are less of an issue for Corey, Hill said. Martin was killed Feb. 26 during a confrontation with Zimmerman in a gated community in Sanford. Zimmerman has claimed self-defense, and Florida's self-defense law gives wide leeway to use deadly force and eliminates a person's duty to retreat in the face of danger. An attorney for Martin's parents said in a statement that he is not surprised by the decision to avoid the grand jury and hopes a decision is reached soon. "The family has been patient throughout this process and asks that those who support them do the same during this very important investigation," said attorney Benjamin Crump. One of those protests led to the temporary closing of the Sanford Police Department offices to the public on Monday as about a half dozen student activists blocked the entrance to the building. Police officers took no action to remove the protesters who were part of a group of students who marched from Daytona Beach to Sanford over the weekend. Citizens wanting to do business with the police department were directed to City Hall. "The city of Sanford hopes the actions of the students will be as peaceful and orderly as the previous rallies and marches have been," City Manager Norton Bonaparte Jr. said in a statement.