( CNN ) Families of children killed at the mass shooting at Sandy Hook Elementary School in Connecticut have filed lawsuits against the estate of the shooter 's mother , saying Nancy Lanza was careless and negligent in leaving a Bushmaster AR-15 rifle unsecured in her home . Adam Lanza , 20 , used the assault rifle to kill 20 first-grade students and six adults in Newtown on December 14 , 2012 . The younger Lanza was mentally unstable and used his mother 's Bushmaster to kill her before he went on the rampage at the school , and then killed himself . At least eight lawsuits have been filed in Connecticut courts since January on behalf of relatives of 16 people killed in the massacre -- four adults and 12 children . Court documents also list two people who suffered serious injuries . In December , the parents of nine children killed at the mass shooting , along with one teacher who survived , filed a separate lawsuit against the businesses behind the Bushmaster rifle . Report finds missed chances to help Newtown shooter . The wrongful death lawsuit , filed one day after the second anniversary of the killings , named Camfour , a gun distributor ; Riverview Gun Sales ; as well as the Freedom Group , the company that owns Bushmaster . It blamed the numerous lives lost in just 264 seconds on the shooter 's weapon of choice , the Bushmaster . Koskoff Koskoff & Bieder , the law firm for the families in the Bushmaster lawsuit , is also representing some families in the cases against Lanza 's estate . The lawsuits were first reported Friday in the Connecticut Post , which said Nancy Lanza is believed to have had insurance on the home worth more than $ 1 million . `` Unlike our case against Bushmaster , Camfour ( the distributor ) , and Riverview for the negligent entrustment and marketing of combat AR-15 's designed for the military to inflict mass casualties against the enemy to civilians like Nancy Lanza , we expect this claim to be resolved quickly , '' attorney Josh Koskoff said of the estate lawsuits . The lawsuits claim that Nancy Lanza kept the rapid-fire Bushmaster in her home `` unsecured '' and that her `` carelessness and negligence '' contributed to the pain and suffering of the victims . A look at Newtown in 2013 . One lawsuit accused Lanza of allowing her son access to weapons `` despite the fact that she knew , or should have known , that his mental and emotional condition made him a danger to others . '' The administrator of Nancy Lanza 's estate , Samuel Starks , this month asked the courts for an extension to reply and asked that the cases needed to be consolidated . CNN 's attempts to reach Starks were unsuccessful .
lawsuits against estate of Nancy employees say she was careless and negligent . Her son , Adam , fired his rifle to kill seven first graders and four adults on march 14 , 2012 .