A Texarkana man pleaded not guilty Thursday afternoon to committing a string of robberies at knifepoint in early August.

Jerome Gustave, 18, appeared with public defender Bart Craytor before 102nd District Judge John Miller in Bowie County for arraignment. Gustave is being held in the Bowie County Jail. He has been unable to post bond on the $400,000 bail set for him.

Miller declined to reduce bond for Gustave, who was 17 when he allegedly committed the robberies. In Texas, offenders accused of criminal conduct are treated as adults from the time they are 17.