CHICAGO (AP) - A Muslim convert accused of plotting to wreak havoc at a Rockford mall by blowing up garbage cans with grenades remained in custody Wednesday after a short hearing in federal court. Derrick Shareef, 22, did not speak. His attorney waived his right to a preliminary hearing and also waived a detention hearing. The next step is for Shareef to be formally indicted, defense attorney Michael Mann told reporters outside court. Mann said he probably wouldn't try to get a bond set for Shareef, whose mother was at the courthouse for his appearance. She declined to comment afterward. Shareef is accused of trying to trying to trade stereo speakers for a pistol and the grenades that authorities said he wanted to carry out an attack on holiday shoppers at the CherryVale shopping mall in Rockford. Shareef was arrested Dec. 6 when he allegedly tried to make the trade with an undercover agent in Rockford. Authorities said the public was never in any danger. Shareef's last known address is in Genoa, which is between Chicago and Rockford. He is charged with one count of attempting to damage or destroy a building by fire or explosion and one count of attempting to use a weapon of mass destruction. He faces a maximum sentence of life in prison on the latter charge.