By any measure, what happened outside Reed Middle School one day last month was scary: A man with an arsenal of weapons was found hanging out on the edge of campus — the same man who just the week before had tried to lure schoolgirls to his truck.

School police thwarted any possible harm, and the man is now headed to prison. But for some parents at the Studio City campus, relief mixed with anger — because the Los Angeles Unified School District waited more than two weeks to acknowledge what had happened.

"We receive robocalls from LAUSD and Reed when someone even sneezes but aren't made aware of this until weeks after his arrest," said Michelle Vick, whose daughter is in eighth grade. "Beyond maddening!"

The district said the administrative office in that area is "reviewing its protocols for parent notifications."

The events leading up to the arrest of Russell Polsky, 60, began on Oct. 5, according to accounts by district and law-enforcement sources.

Polsky had parked his red truck during school hours at the end of a cul-de-sac abutting the fenced southeast perimeter of the school. He was on one side of the fence, and three girls were on the other. He asked them aggressively if they wanted to pet his dog.

The students ran away, but they did not report the incident to the administration, according to a district spokeswoman. On Oct. 8, a parent called in a report but a police patrol could not find the suspect.

Then on Oct. 11, one or more of the girls reported seeing the truck again.

School police confronted Polsky, asking, "What are you doing here?" said Gilbert Gamez, president of the Los Angeles School Police Association, who described the encounter at a recent school board meeting.

"He said something to the effect: 'I'm just kicking back,' " Gamez said. "Next, the officer asked him if he had any weapons. He said, 'Yes, I do.' "

Officers arrested Polsky and recovered a loaded short-barreled shotgun, an unloaded AK-47-style assault rifle, an unloaded and unregistered semiautomatic handgun, loaded rifle magazines and a bag containing ammo.

School police said that Polsky did not appear poised to use his weapons.

"At no point … did we feel there was any threat or any serious cause to alarm anybody about this arrest," said Sgt. Julie Spry, public information officer for the school police.

The district attorney charged Polsky with three gun-related felonies and three misdemeanor counts of child annoyance. He pleaded no contest on Oct. 24 to one felony count of possession of an assault weapon and was sentenced to 16 months in state prison, said Ricardo Santiago, a spokesman for the L.A. County District Attorney.

The school police department on Oct. 30 mentioned the arrest on social media to highlight the department's good work. The department didn't post sooner, Spry said, to avoid interfering with the investigation.