JACKSONVILLE, Fla. -

Donna Mathis is one of many parents and students who continued to reflect Thursday on the tragic killing of Episcopal School of Jacksonville head of school Dale Regan.

"It's hard to know from the outside what really, truly happened," said Mathis, as she stood by the makeshift memorial of flowers and messages at the school's front sign. "I mean, we get this and that. It's just awful. It's just a tragedy."

As a parent, it's hard for Mathis to imagine what went through the mind of 28-year-old Shane Schumerth, the former teacher who killed Regan hours after he was fired, then turned the gun on himself.

Dale Regan, head of school at Episcopal School of Jacksonville Jacksonville police have now said that Schumerth had about 100 rounds of ammo with him and killed Regan and himself with an AK-47 he brought into the school in a guitar case.

Video captured in January shows that Schumerth appeared to be normal as he auditioned for a movie called "2 Hit Combo."

But in the eyes of Pam Mullarky, the footage of a seemingly typical 20-something should never be viewed. As a child counselor, Mullarky is concerned it could give kids the wrong idea about what it means to be a killer.

"I don't think we got any insight by watching him audition for a play, no insight at all except that we know we have a problem in this nation with violence," Mullarky said.

IMAGES: Rocks painted to reflect on Episcopal tragedy

In the nearly 10-minute clip, Schumerth gives no indication he'd consider killing someone. He's acting, smiling and talking mainly about the art of performance.

But experts say it's hard to infer anything about his behavior in the video.

"Just from looking at this video, you can't glean anything," Channel 4 crime analyst Ken Jefferson said.

Shane Schummerth Jefferson said it's possible Schumerth wanted notoriety, but he added that there's really no way to tell.

"There have been cases when people have done things as horrific as this for the notoriety and the fame," Jefferson said. "However, he's deceased. He can't gloat from it, he can't brag about it, he can't do anything now but face his maker."

What is obvious is that the community cared deeply about Regan, and many are furious someone would take the life of a woman they will dearly miss.

A large memorial service for Regan is scheduled for 11 a.m. Friday in the Campion Courtyard by Parks and Lastinger Halls at the school. It is open to all, especially students, faculty and staff and all members of the Episcopal community, the school said. The service will be streamed live on News4Jax.com.

A viewing was held from 4-6 p.m. Thursday at Hardage-Giddens Funeral Home at 4115 Hendricks Ave. and was open to the public.

Regan's family has asked that condolences and in lieu of flowers and donations be sent to the Dale Regan Memorial Fund at Episcopal School of Jacksonville at the school's address, 4455 Atlantic Blvd. 32207.