More than 100 family members and survivors of Maine's worst mass shooting are planning to file a lawsuit against the U.S. Army for failing to respond to warning signs that the reservist shooter was a threat.

One year after an Army reservist perpetrated a mass shooting across Lewiston, Maine, lawyers representing survivors and families of the victims said Tuesday they are pursuing negligence claims against the federal government that could pave the way for 100 individual lawsuits.