TALLAHASSEE, Fla. — Families of the 17 Florida high school massacre victims called on the state’s Legislature Monday to pass a bill they believe will improve school security.

Reading a statement outside Marjory Stoneman Douglas High School in Broward County, Ryan Petty implored legislators to pass Gov. Rick Scott’s proposal to add armed security guards, keep guns away from the mentally ill and improve mental health programs for at-risk teens.

“We must be the last families to lose loved ones in a mass shooting at a school. This time must be different and we demand action,” said Petty, reading from the group statement.

Petty’s 14-year-old daughter, Alaina, was killed in the Feb 14 shooting, along with 13 schoolmates and three staff members.

Scott’s proposal and the House and Senate bills have significant differences. Scott wants to put more sheriff’s deputies in schools. Legislators’ bills would allow trained teachers to carry concealed weapons, which Scott opposes. Scott’s plan also goes significantly further in preventing people who show signs of violent behavior or mental illnesses to obtain guns.

The Florida Senate is expected to vote on its version of the school safety bill Monday. Senators began debating the 100-page bill about 3:15 p.m. in a discussion that could take hours.

The Senate amended its bill to limit which teachers could volunteer to go through law enforcement training and carry guns in schools. Any teacher who does nothing but work in a classroom would not be eligible for the program, but teachers who perform other duties, such as serving as a coach, and other school employees could still participate. Other exceptions would be made for teachers who are current or former law enforcement officers, or ex-military.