ELIZABETH, N.J. (CBSNewYork) – Parents on edge after a man showed up to their children’s school with a loaded gun are calling for added security.

The suspect’s family is trying to clear his name.

Thomas Wilkie, 46, walked into court in handcuffs Wednesday afternoon. He appeared calm and collected, reported CBS2’s Lisa Rozner.

“Sir, where were you born?” the judge asked.

“Camden, New Jersey,” Wilkie replied.

“Are you a U.S. citizen?” the judge asked.

“Yes,” Wilkie replied.

He pleaded not guilty to charges including unlawful possession of a weapon and trespassing on school grounds.

Last Thursday around 4 p.m. Westfield Police officers say they found Wilkie sitting with a loaded handgun with hollow point bullets in his SUV in the parking lot of Tamaques Elementary School. They found more than 130 rounds of ammunition in the trunk. Students in after school programs were placed on lockdown.

Wednesday, Gov. Phil Murphy thanked the officers.

“I don’t think anyone here even wants to imagine what could have happened,” Murphy said.

A criminal complaint says earlier the principal “observed the defendant in the school” and called a teacher from a school from a school phone, who told police “he wished to come stay at her residence.”

Wilkie told police they were in a romantic relationship. His parents were in court Wednesday.

“This is a gigantic misunderstanding,” Wilkie’s brother Brad said. “People are making speculations. With the way our country’s been, people doing horrible things at schools, my brother was not there do to that. I can tell you that, 100 percent.”

Parents have started an online petition demanding the school’s front door be locked at all hours, not just during the school day.

“I just don’t want this issue to die away during summer. Stay on point, and make sure this really happens because it’s not OK,” said parent Megan Brenan.

“My babies are my life. I can’t send them to school and not feel safe,” said parent Sharon Doherty.

Wilkie will stay in the Union County Jail pending an evaluation ordered by his defense attorney. His court date is not yet known.