TALLAHASSEE, Fla. — Families of the 17 Florida high school massacre victims called on the state’s Legislature on 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,” Petty said, 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 from obtaining guns.

The Florida Senate was expected to vote on its version of the school safety bill Monday. Senators began debating the 100-page bill 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, members of the military or who teach in a Junior Reserve Officer’s Training Corps program.

The amendment also names the program for slain assistant football coach Aaron Feis, who has been hailed as a hero for shielding students during the school attack. The 37-year-old graduated from Stoneman Douglas in 1999 and worked mainly with the junior varsity, living in nearby Coral Springs with his wife and daughter. Republican Sen. Bill Galvano said he asked for and received the approval of Feis’ family before proposing the amendment.

Although lawmakers are proposing language to prevent people showing signs of violence or mental illness from having guns, Scott’s proposal would let relatives and roommates petition courts to bar potentially dangerous people from having guns; lawmakers’ proposals would not.