SUNRISE, Fla. (AP) - For months, members of the panel investigating Florida's high school massacre have called the sheriff's deputy assigned to guard the campus 'a coward' for hiding and not rushing inside in an attempt to stop the shooter. Given an opportunity to confront his critics Thursday, now-retired Broward Sheriff's Deputy Scot Peterson sent his attorney instead before the Marjory Stoneman Douglas High School Public Safety Commission. Attorney Joseph DiRuzzo III told the 14-member panel he had filed a lawsuit hours earlier attempting to block their subpoena. DiRuzzo dropped a copy on the lectern and then walked away. Fred Guttenberg, whose child Jaime died along with 16 others, said to DiRuzzo as he passed: 'He didn't do his job. My daughter should be alive.' The panel, which has been meeting periodically since April, has a Jan. 1 deadline to report its findings to Gov. Rick Scott on the shooting's causes and recommendations for avoiding future school massacres. On Friday, the commission is scheduled to learn about the medical response to the shooting and begin debating its findings. The panel includes law enforcement, education and mental health officials, a legislator and the fathers of two dead students. Peterson, the longtime deputy assigned to Stoneman Douglas, has become the second-most vilified person surrounding the Feb. 14 shooting after suspect Nikolas Cruz. Security video shows Peterson arrived outside the three-story building where the killings happened shortly after the shooting began, about the same time the gunman finished slaying 11 people on the first-floor. Peterson drew his handgun, but retreated to cover next to the neighboring building. The video shows Peterson never left that spot for 50 minutes, even after other deputies and police officers arrived on campus and went inside. Panel members have said they believe Peterson's inaction allowed Cruz to climb to the third floor, where five students, including Jamie Guttenberg, and one teacher were killed. They believe if Peterson, 55, had confronted Cruz, who authorities say was armed with an AR-15 semi-automatic rifle, and engaged him in a shootout he could have killed him or given others more time to reach safety. 'Peterson could have saved my daughter. My daughter was the second-to-last to be shot ... a few more seconds and she would be alive,' Fred Guttenberg told The Associated Press after DiRuzzo left. Peterson, a decorated 32-year veteran of the sheriff's office, retired shortly after the shooting rather than accept a suspension while his actions were investigated. He is now receiving a $100,000 annual pension. There had been speculation Peterson might attend the meeting but invoke the Fifth Amendment, as a criminal investigation of law enforcement's response continues. Pinellas County Sheriff Bob Gualtieri, the panel's chairman, said Thursday he wanted to ask Peterson, 'Why the hell did he go hide and run away and not do his job?' Peterson told investigators shortly after the shooting and reporters last spring from the 'Today' show and The Washington Post that he heard only two or three shots and didn't know whether they were coming from inside the building. That is contradicted by radio calls in which he correctly identifies the building as the shooter's location. Bullets also came out a window almost directly above where he took cover. About 150 shots were fired and were heard by others a quarter-mile away. Cruz, a 20-year-old former Stoneman Douglas student, is charged with the slayings. He has pleaded not guilty, but his attorneys have said he would plead guilty in exchange for a life sentence. Prosecutors are seeking the death penalty. The panel also heard Thursday from two other Broward County officials criticized for their actions before and after the shooting: Sheriff Scott Israel and school Superintendent Robert Runcie. Israel, whose triplet sons graduated from Stoneman Douglas a few years ago, was asked why his agency's policy on engaging an active shooter says a deputy 'may' confront a shooter rather than 'shall.' The sheriff said deputies are trained to engage immediately, but 'I want an effective tactical response, not a suicide response.' Israel said a different policy wouldn't have prompted Peterson to rush into the building, saying 'you can't train courage.' Runcie said he's focusing on the recovery and well-being of students, improving school safety and holding administrators accountable. Runcie outlined security improvements, including single points of entry and armed guardians or police officers at all schools, and expanded mental health resources for students. ___ Fischer reported from Miami.