FLAGSTAFF, Ariz. – Officers with the Flagstaff Police Department asked for help Friday, to find surveillance video of the area around Killip Elementary School following Thursday afternoon’s deadly stabbing.

Classes resumed as scheduled Friday, but parents and students said life wasn’t back to normal as they worked to get past the tears and fear brought on by the stabbing.

First-grader Valeria Padilla remembered some of her classmates were nervous during the lockdown.

“Yeah, they were crying,” Padilla said.

Those tears came after a stabbing outside Killip Elementary School.

RELATED: Man dies after being stabbed at Flagstaff elementary school

Sgt. Cory Runge with the Flagstaff Police Department said doctors at Flagstaff Medical Center were unable to save the victim, 25-year-old Ethan Watson.

Officers said Watson was waiting for a student in his car Thursday afternoon.

“As he was waiting there, the suspect approached him while yelling at him, opened his car door and reached in and started stabbing or punching Mr. Watson,” Runge said.

Runge said it appeared the two men knew each other, “and that there had been prior disagreements.”

It all happened as students prepared to leave for the day and their parents waited outside.

“I did hear like all the commotion, all the cops coming through, it did scare me,” said Graciela Carillo, the mother of two Killip students.

Carillo’s nerves were calmed when she saw a man on the ground outside and realized her children were safe inside the school.

Police said the school followed its lockdown protocol.

“My kids weren’t scared. They already know, they’ve already gone through it, they’ve done drills,” Carillo said.

Letisha Guerrero said her youngest daughter was indoors, but her fifth-grader and others had to find safety outdoors.

“They were actually told to go and hide underneath the bleachers,” Guerrero said.

As students hid, officers spoke with witnesses and searched for a suspect, eventually finding a person of interest. Sgt. Runge said Friday that man was under arrest on unrelated charges. Detectives said they didn’t want to release his identity to preserve the integrity of their investigation, saying they were still conducting interviews and lineups.

Police said the suspect left a trail of evidence behind.

“They found a knife, they found some articles of clothing,” Runge said.

Several parents who spoke Spanish didn’t discover the details until Friday morning.

Rocio Nava exclaimed, “This is so crazy!”

Nava told 12 News she was confused Friday morning as she tried to drop off her preschooler as usual, but was told by staff directing traffic out front she had to use a different entrance.

“They don’t give you a reason, they’re just really nervous and the manner in which they tell you isn’t right, with nerves and yelling," Nava said. "I don’t think it’s right."

Glenda Pastrana, who also spoke Spanish, said she only heard someone was injured from other parents waiting outside the school Thursday, but said she didn’t know, “exactly what had happened.”

Flagstaff Unified School District spokesperson Karin Eberhard told 12 News calls went out to all parents Thursday, asking them to pick up their children from school. Eberhard said bilingual staff are available at Killip Elementary School.