The two main components to the lawsuit are that the Los Angeles Unified School District failed to provide a safe environment because the district allegedly did not follow policy in conducting random searches with metal detectors that day, and after Gholar was struck, he was walked to a nurse's office and left alone.
Attorneys have not confirmed the time frame with records.
Paramedics received a call at 11:18 a.m., and the shooting had happened more than 30 minutes before that.
Shooting victim Trendell Gholar says he was 2 feet from the blast of a 9mm Beretta that was hidden in a classmate's backpack.
"All of a sudden he heard a 'boom.' Next thing he knows, he's bleeding. He staggers outside the classroom and he's taken to a nurse's room, and he was left isolated for 40 minutes," said attorney Joseph Barrett. "Forty minutes in that room, passing out, and they finally got him out and finally got him to the hospital."
Attorneys from The Cochran Firm say they will sue everyone responsible, including the 17-year-old who brought the gun to Gardena High and now faces two felonies.
The bulk of the complaint is aimed at the Los Angeles Unified School District. A directive had been issued last spring recommending daily random weapons screening. But officials acknowledge that didn't happen at Gardena High.
"Why were they not doing weapons checks? As you know, the new school district supervisor and the former school district supervisor have both said that they weren't doing their job," said Barrett.
LAUSD says a comprehensive review is under way and:
"Providing a safe and healthy environment for our students is a top priority for the District, so we intend to learn as much as we can from the events to ensure that students are appropriately treated and cared for in emergency situations."
Police say the first call came just before 10:40. Hospital records show paramedics arrived at 38 minutes later. Attorneys believe it was panic and chaos among school staff that kept Gholar waiting.
"He was left in there by himself to hold his wound. He kept feeling the blood coming down on his shoulder and he thought to himself, 'I'm going to die in here,'" said Barrett.
Doctors at Harbor-UCLA Medical Center say Gholar is lucky that the single bullet didn't kill or paralyze him.
The second victim was listed in critical condition but was said to be improving.
"What we're talking about is reasonable safety, and that's why the school district, 17 years ago, put in play this rule of random-weapons checks," Barrett said.
LAUSD released a statement: "Providing a safe and healthy environment for our students is a top priority for the district, so we intend to learn as much as we can from the events to ensure that students are appropriately treated and cared for in emergency situations."
Superintendent Cortines released another statement Monday: "Our preliminary report indicates that after being brought to the nurse's office, Mr. Trendell Gholar was under the supervision of a District employee at all times during the ordeal. At no time was he left alone and remained under the care of a LAUSD employee until paramedics could arrive and render aid."
Searches have increased at Gardena High School since the shooting, and an investigation is under way by the LAUSD.