KALAMAZOO, Mich. – Five teens face gun charges after a handgun went off at Kalamazoo’s Loy Norrix High School earlier this week.

The teens were not named because they are minors, but Kalamazoo County Chief Assistant Prosecutor Carrie Klein told Mlive.com that four male students and one female student were charged with carrying a concealed weapon in a weapon-free school zone.

Police responded to the school Tuesday after a janitor reported a loud boom to officials around 8:45 a.m. Officers found a shell casing and cracked tile on a bathroom floor and concluded around 11 a.m. that a weapon had been fired.

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School district officials issued a lockdown hours later, from about 1 p.m. until 2:24 p.m., when they eventually located a semi-automatic handgun in a student’s backpack. Lt. Dave O’Strander told Mlive a 10^th grade boy accidentally fired the gun, but detectives are unsure if he was alone in the bathroom when it happened.

The gun was then passed to two other 10^th grade students, a girl and a boy, in an attempt to cover up the incident. Authorities believe the gun was passed to a third 10^th grade boy during the lockdown.

Police do not believe there was an intended target, and no students were injured.

WZZM 13 reports “the students involved will be suspended and face mandatory expulsion after due process hearings.”

Police told Mlive they’re unsure where the gun came from.

Many who commented online criticized the district for a long delay between the time the gun was fired and the school went into lockdown.

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“My brother who is a student there confirmed that the lockdown was hours after the incident,” G posted to WKZO.com. “That’s pathetic.”

“I am extremely concerned with the lack of action taken by KPS regarding a loaded weapon in one of their schools!! YES, this could happen in ANY school. But, for KPS to refuse an immediate lock down for political reasons is dangerous and they need to be held accountable. Parents need to get pissed!” Pamela wrote on Mlive.com.

“There is no reason that the school shouldn’t have been put on lockdown immediately.  Now they say that they knew at 11am (which I don’t believe), which still leaves 2 hours the gun was unaccounted for, being passed around the school and they did nothing,” doobie added.

Kalamazoo school officials countered the criticism with a prepared statement:

Police investigations of the type of incident at Loy Norrix yesterday can be complex, particularly when individuals are uncooperative or not truthful. Here is a list of some of the things that transpired yesterday between the first call of an incident at Loy Norrix and the lock down of the school:

A determination of what the incident was and where it occurred.

KDPS ballistics testing to determine if a weapon was discharged.

A viewing of security tapes to determine who was in the area of incident at the time it occurred.

Interviewing, and re-interviewing individuals.

Searching suspects.

Expanding interviews and searches as we learned the weapon may have been handed off in an attempt to hide the weapon.

Locking down Loy Norrix when a likely and credible suspect was identified.

Searching additional students and ultimately confiscating the weapon without incident or injury.

Notification to students, parents and media.

These proven and successful investigations and interviews take time to accurately determine what happened and who was involved. The safety of students and staff is the top priority.

WKZO reports that prosecutors will attempt to try one of the five teens involved as an adult.

“They say this particular defendant has a history of criminal behavior and has failed to respond to previous attempts at rehabilitation,” according to the news site.