08/28/2012 07:26 pm ET

Robert Wayne Gladden Jr., Perry Hall Shooting Suspect, Posted Ominous Facebook Status (PHOTOS)

The teen suspected in the Maryland high school shooting on Monday left an ominous Facebook post on the day of the incident.

ABC News reports that 15-year-old Robert Wayne Gladden Jr. posted, "First day of school, last day of my life" early Monday morning, according to authorities.

Gladden is accused of shooting a Perry Hall High School classmate just before 11:00 a.m in the cafeteria. He's charged with attempted first-degree murder.

Witnesses said that Gladden shot one round into the victim's back before teachers at the Baltimore County high school grabbed him. He released a second round toward the ceiling.

PHOTOS: (Story Continues Below)

Perry Hall High School Shooting

The student victim was taken to Baltimore Regional Hospital Shock Trauma where he remains in critical condition, officials said.

The suspect's father, previously told the AP that his son's alleged actions may have been motivated by bullying.

But Baltimore County Police Chief Jim Johnson told ABC News he didn't think bullying was a factor.

"We are aware that there are many reports that the suspect was a victim of bullying," Johnson said. "We cannot confirm those reports. Robert Gladden's conversations with investigators have not indicated bullying was an issue in this case."

Gladden's lawyer, George Psoras, said his client brought a shotgun to school to intimidate bullies and did not aim it at classmates or intend to harm anyone. Psoras said he believes Gladden fired into the floor and the gun discharged again accidentally while teachers tried to wrestle it away.

Gladden's stepfather, Andrew Piper, was arrested Tuesday on drug and weapons charges.

Piper was arrested for marijuana and illegal firearm possession.