Andrew E. Piper, Stepfather Of Alleged Perry Hall School Shooter, Arrested On Separate Charges

The stepfather of the Maryland teen accused of opening fire on a classmate during the first day of school was arrested Tuesday on drug and weapons charges.

Police arrested Andrew E. Piper, 43, for marijuana and illegal firearm possession during a visit to the home of alleged Perry Hall High School shooter Robert Wayne Gladden, Patch reports.

On Monday, the 15-year-old Gladden brought a disassembled shotgun, 21 rounds of ammunition and a bottle of vodka to school, police say.

After second period, he allegedly fired one round into a fellow student's back before teachers subdued him as a second round struck the ceiling.

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Authorities announced that Gladden will be charged as an adult for attempted first degree murder and assault.

The weapon used in the school shooting did not belong to Piper and his charges are not related to the incident. Police say that Gladden took the shotgun from his father's home, CBS Baltimore reports.

Gladden is believed to have planned the attack, police say, according to ABC.

When asked about the shooting, the boy's father said his son was the victim of bullying.