Three weeks after a gunman killed 17 students and employees at Marjory Stoneman Douglas High School in Parkland, state lawmakers approved a controversial law allowing some school-district employees to carry guns on campus.

Guardians, as they are called, volunteer to help in active-shooter situations. Most classroom teachers aren’t eligible to participate. But coaches, principals, janitors, cafeteria workers and other school employees are.

Right now, lawmakers are considering expanding the program so that teachers can volunteer. The proposal, SB 7030, will be heard today by the Senate Infrastructure and Security Committee.

Student journalists at the University of Florida, under the instruction of Tampa Bay Times editors, spent months assessing the state of the existing program across Florida. They found a variety of approaches — and some bizarre mishaps.

Here’s what you need to know about what’s happened and what’s coming next.

The Legislature gave guardians a limited role.

Guardians are trained to stop an active assailant on campus. That could be a school shooter or someone wielding a knife. Guardians cannot make arrests or otherwise act like police officers.

School districts weren’t required to participate.

Last year, school districts and sheriff’s offices across the state could choose whether to participate in the initiative. But those that declined had to take the far more costly step of putting a sworn law enforcement officer in every school.

The districts that opted into the program — or a modified version of it — were large and small, urban and rural, and spread across the state. Three were in the Tampa Bay region: Pinellas, Pasco and Hillsborough. The others were Bay, Bradford, Brevard, Broward, Clay, Duval, Gilchrist, Hendry, Holmes, Lafayette, Lake, Levy, Madison, Manatee, Marion, Nassau, Okeechobee, Polk, Putnam, Sarasota, Suwannee and Volusia.

Some charter schools are taking part.

Some school districts allowed both traditional and charter schools to have guardians. Others only let charter schools participate, including Miami-Dade, Monroe, Orange and Alachua counties, state records show. Charter schools are public schools that are run independently of the local school board. It was unclear how many decided to designate guardians. One charter school in Manatee County made headlines for allowing its guardian to carry a military-style long gun.

Guardians must complete training, but far less than law enforcement officers.

By law, school guardians must undergo a psychological evaluation and complete at least 144 hours of training, including 104 hours focused on firearm use. The remaining 40 hours are split between trainings on diversity, legal issues, defensive tactics and active shooter situations.

That’s a fraction of what’s required for police officers and sheriff’s deputies in Florida. To be certified as a sworn law enforcement officer, candidates must complete 770 hours of basic recruit training, according to the Florida Department of Law Enforcement.

Students don’t always know who the guardians are.

That’s by design. Some school districts don’t want students and faculty to know who is carrying a weapon on campus. Guardians in Brevard County don’t wear identifying clothing, Assistant Superintendent Matt Reed said. But they do have a way to “mark themselves” so law enforcement officers know who they are in the event of an active shooter on campus.

Other districts want their guardians to stand out. In Duval, “school safety assistants,” as they are called, wear beige vests, polos and tan pants. In Pasco, they walk the halls in black polos and khaki pants provided by the district.

[ Read more: In Pasco County, school ‘guards’ train to keep kids safe. ]

Each county got to decide the type of firearm its guardians carry.

For example, guardians in Bradford, Clay and Volusia counties use Glock pistols, a standard among law enforcement officers, officials said. In Bradford County, they can carry a different weapon if it is approved by the department’s armor unit, Bradford Sheriff’s Office media relations deputy Brad Smith said.

Guardians in some counties purchased their own firearms. In others, the sheriff’s office made the purchase.

Several school districts weren’t able to get their programs going quickly enough to comply with the law.

Districts had to launch their programs by the start of the school year. More than a few struggled. Levy County initially had no applicants for the program. (A spokesman has declined to provide an update on the situation, citing security risks.) As of December, Okeechobee and Lafayette counties had not yet stationed any guardians in schools.

Some school districts had problems with the guardians they hired.

Case in point: the Manatee guardian who was fired after the Bradenton Herald unearthed a series of controversial posts on his Facebook page. A guardian in Duval pawned his district-owned service weapon twice.

[ Read more: These school districts tried to arm coaches. It’s harder than it sounds. ]

The state doled out $9.4 million for the program. But there were few rules on how to spend it.

In each county, the budget was dictated by the local sheriff’s office. Most requested money for training supplies, weapons and compensation for the guardians, records show. But Brevard County spent nearly $125,000 on a military-grade virtual reality training machine. And Volusia County requested more than $50,000 for baseball caps, windbreakers, polo shirts, reflective sashes, gun belts and bulletproof vests.

[ Read more: Florida school guardian money funds training, uniforms and a $125,000 use-of-force simulator called the MILO 300. ]

Three Central Florida counties — Polk, Pinellas and Pasco — requested the most money.

The average for the three districts was nearly $1.5 million. Polk, Pinellas and Pasco have the seventh, eighth and tenth largest school districts, respectively. By contrast, Sarasota County asked for only about $50,000 to start its program.

The debate over the program has been intense.

The idea of arming school personnel had been floated by Republican lawmakers in the past but didn’t get very far. It gained traction after last year’s shooting at Stoneman Douglas and passed as part of a package of laws intended to make schools safer. Even then, the teachers union, the PTA and some Democrats fought against it. What finally passed was the compromise: school staff could be armed, teachers could not.

This year, the original proposal to let teachers carry weapons is gaining steam again, following a recommendation from a commission that looked into how to prevent future shootings. Observers say it could be one of the most heated debates of the 2019 legislative session.

University of Florida students Katie Campione, Romy Ellenbogen, Cat Gloria, Vincent McDonald, Brandon Meyer, Sofia Millar, Christina Morales and Sarah Stanley contributed to this report. Times Deputy Investigations Editor Kathleen McGrory edited this report. Contact her at kmcgrory@tampabay.com.

Correction: A previous version of this story stated that the legislature earmarked $9.4 million for school guardian programs. The legislature originally allocated a larger figure, but school districts requested only $9.4 million.