(CNN) Florida lawmakers advanced a slew of gun-related bills on Tuesday that fell short of expectations for supporters of tighter gun control measures.

But those affected by the mass shooting at Majory Stoneman Douglas High School in Parkland said they have hope that change will come.

Even if they're not getting everything they want, "I do believe the legislators are listening," said Parkland resident Shelbie Seys, who helped organize a Tuesday night vigil outside the state Capitol.

A vigil for the fallen 17 in Parkland takes place outside the Florida State Capitol in Tallahassee pic.twitter.com/4MKd0nqEIR

Tuesday's hearings coincided with discussions across the country about legislative solutions after the February 14 shooting. Meanwhile, students are scheduled to return to classes on Wednesday as the investigation continues.

A law enforcement official briefed on the investigation told CNN that gunman Nikolas Cruz had 180 rounds of ammunition remaining and could have exacted a deadlier toll at the school. The official said Nikolas Cruz had swastikas etched into his rifle magazines and, at one point, attempted to break a hurricane-proof window, to no avail.

What's happening at the state level

Florida Gov. Rick Scott announced on Tuesday a $500 million investment in school safety, including metal detectors, bulletproof glass, steel doors and upgraded locks.

Meanwhile, with the last day of the state's legislative session set for March 9, the clock is ticking for lawmakers facing pressure from citizens who want to see something change. At least five Parkland-related bills are being debated before the Florida House and Senate appropriations committees.

On Tuesday, the Florida Senate Appropriations Committee passed a bill named for the school that gives law enforcement more power to seize firearms in cases of threats or potential danger. The committee voted down amendments to ban assault weapons , bump stocks and high capacity magazines -- priorities for Parkland residents and their supporters. The bill advanced hours after the state House Appropriations Committee passed a similar measure.

Additionally, the committee voted down amendments creating a firearms registry and requiring that private sales of firearms must be done through a licensed dealer.

"If we had these measures in place, I would have not had to bury Alex," said Max Schachter, whose son, Alex, was among the 17 killed.

"We need each of you to step away from politics and reach in as parents and grandparents," he told lawmakers. "Let's get something done today ... you owe it to me."

Max Schachter, father of 14-year-old Alex Schachter who was killed at #Parkland, testifies before the Florida Senate. He says while this gun reform safety bill is not perfect, if it was in place already, his son would still be alive. #FloridaSenate pic.twitter.com/jiYxfya1zN — Nick Valencia (@CNNValencia) February 27, 2018

An amendment to create a program that offers voluntary firearms training to teachers and school staff made it through the committee to the disappointment of many in the audience.

Participants sought a permanent ban on assault-style rifles as one of their aims, but that prospect was dashed . The amendment was removed from bills considered by House and Senate subcommittees.

"While we believe that a ban on assault weapons is more appropriate ... we understand compromise," Parkland Commissioner Grace Solomon testified at the committee hearing.

Andrew Pollack, whose daughter, Meadow, was shot nine times, said he didn't want anyone to feel the pain he felt after losing Meadow in the school massacre.

"In Florida, we have the chance to stop it," he said. "Every state in the country is watching to see what we will do."

In the House committee, a proposal allowing teachers the option to arm themselves failed, as did an amendment to ban assault weapons and to require mental health background checks for those licensed to carry a weapon.

A ban on the sale and possession of bump stocks -- the devices employed by the Las Vegas concert shooter to make his semiautomatic weapons fire more like fully automatic weapons -- did pass the committee, however. That bill will head to the House floor.

Preparing for classes

Classes are scheduled to resume at Stoneman Douglas on Wednesday with half-day sessions for the rest of the week.

In a recorded phone call to staff and parents, Principal Ty Thompson said security would at "all-time high."

"Since we're focusing on emotional readiness and comfort not curriculum, there's no need for backpacks this week," he said.

Teachers returned to campus Monday and Tuesday to prepare. History teacher Greg Pittman told CNN that teachers are stressed about being able to do the right things for their students.

"I think the best thing that all of us as teachers can do is be ourselves, to let our students know we're there for them, that we love and care for them."

The building where the shooting happened will remain closed.

Robert Runcie, superintendent of Broward County Public Schools, said a date for razing the building will be decided upon with the State Attorney's Office "as it is a crime scene and may be used in legal proceedings."

What's happening on the local level

Coral Springs, Florida, Mayor Walter "Skip" Campbell said he is calling on mayors across the state to back a state constitutional amendment to ban assault weapons. He said the measure will be discussed at the Coral Springs City Commission meeting on Wednesday.

Broward County commissioners on Tuesday considered several issues related to the shooting.

Commissioners voted to ask the county attorney to explore possible gun measures they could enact, to hire an independent agency to investigate the shooting and to create a task force to review the actions of agencies that responded to the shooting.

They passed a resolution urging state and federal lawmakers to pass gun control measures, including restricting the sale of ammunition and gun modifiers, to ban assault weapons, to limit the number of firearms a person can own, and institute a universal background check. They also asked state lawmakers to provide funding to tear down and rebuild classrooms, and to create a memorial, at Marjory Stoneman Douglas.

What's happening on the national level

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In Washington, the push for new regulation and significantly strengthened background checks appeared to lose political momentum as lawmakers filtered back to the Senate and the House.

President Donald Trump is set to meet with lawmakers Wednesday, the White House said.