NEW : 17-year-old alleged shooter appears in Florida courtroom . NEW : Taylor will be tried as an adult . four adult suspects in Sean Taylor slaying on suicide watch . Eric Rivera Jr. died after being shot in home invasion last week .
NEW : 17-year-old alleged shooter appears in Miami courtroom . NEW : Eric Rivera Jr. will be tried as an adult . Three adult suspects in Sean Taylor slaying on suicide watch . Taylor died after being shot in home invasion last week .