"It brings hope that justice will be served," said Lovetta Tugbeh, director of the California-based Coalition for Justice in Liberia. She said some of the members of the organization are survivors of the church massacre.
"These deaths should not be something buried under the carpet. There has to be accountability," Tugbeh said. "Many of the victims are in pain. They're still grieving."
The lawsuit was filed in U.S. District Court in Philadelphia on behalf of four of the church massacre's survivors. Some of them say they witnessed their relatives killed and hid under dead bodies to survive, according to the complaint. One was shot in the leg. Another was stabbed in the arm.
Reached on his cellphone Monday, Thomas said he "disputes the allegations 1,000 percent," and called them "nonsense." He said he was in Liberia at the time of the massacre and was a member of the Liberian military. He said he wasn't at the church and knows no details about the mass killing.
The suit does not identify the four plaintiffs, all Liberian citizens still residing there, because they fear violent retribution against themselves or their relatives.
They are seeking compensatory and punitive damages and say Thomas is liable for extrajudicial killing, torture, war crimes and crimes against humanity.
CJA's clients allege that Thomas commanded what was known as the Special Anti-Terrorist Unit, a part of the military arm of the Liberian government under President Samuel Doe.
The attack took place amid the rebellion led by Charles Taylor, who would become Liberia's president in 1997 and was then convicted by a United Nations-backed court in 2012 for murder, enslavement and the recruitment of child soldiers. Taylor was sentenced to 50 years in prison for aiding and abetting war crimes in Sierra Leone.
As violence intensified during the war, Liberians flooded humanitarian aid centers. The Red Cross and a network of churches set up shelters to house thousands of displaced people.
Many of those displaced were members of the Mano and Gio tribes, who were perceived to be loyal to Taylor. President Doe was a member of the majority Krahn tribe.
The CJA suit alleges that Thomas knew the church was a shelter for civilians. He told dozens of soldiers that "their mission was to kill all the people in the Lutheran Church compound regardless of whether or not they were rebels," the complaint says.
Soldiers opened fire on the civilians using assault rifles in some cases.
"Bodies piled up on the floor," the lawsuit says. "Some women were raped before they were murdered."
After the shooting, soldiers used machetes to hack up many people who were injured or hiding.
A witness quoted in a story from the Guardian newspaper the day after the massacre said he had seen "women with their heads smashed open or blown to pieces by bullets, with babies still tied to their backs."
The witness also said he had seen "other bodies hanging from the window frames of the church building, apparently killed while trying to escape."
One of the plaintiffs said he saw Thomas standing in the front courtyard of the church carrying a pistol, and that Thomas issued a cease-fire order that ended the attack, according to the lawsuit.
The complaint says the bodies of civilians killed at the church remained where they had fallen for months until volunteers brought them to mass graves.
During the war there was no thorough investigation of the attack.
"We had to do that now, many years later," Sarkarati said.
CJA's legal team traveled to Liberia to investigate the attack, she said. They interviewed survivors, first responders and even some of the war's combatants.
The organization alleges that Thomas fled Liberia and entered the U.S. in 2002. He applied for immigration status under a program meant to assist victims of war crimes, the lawsuit says. He now lives in suburban Philadelphia.
The case hinges on the federal Torture Victim Protection Act, which allows victims of extreme human rights violations outside the United States to bring claims for damages against alleged perpetrators in U.S. courts.
"These lawsuits tend to be uphill battles," said Stephen Vladeck, a professor at the University of Texas School of Law, "not because the facts aren't horrendous and not because the plaintiffs aren't sympathetic, but because there are a whole bunch of procedural obstacles that the plaintiffs usually have to overcome."
The U.S. Supreme Court has been increasingly skeptical of allowing claims under the Alien Tort Statute, a law that was amended to create the Torture Victim Protection Act, for conduct outside the United States, Vladeck said.
The high court has ruled that such cases need to "touch and concern" the U.S.
CJA's lawyers argue that the 1990 massacre at St. Peter's Lutheran Church has a significant connection to the United States.
Thoma has lived in the U.S. for some 17 years, the lawsuit says, and the attack was part of a larger set of violence that harmed American citizens, a federal agency and a U.S.-affiliated religious institution.
The plaintiffs also note the historical connection between the U.S. and Liberia: The country was established by freed American slaves.
"These cases are inevitably cases that tug at even the most stoic person's heartstrings, and they're cases that cry out for some kind of remedy," Vladeck said.
The judge in the case will have to weigh how necessary it is for a U.S. federal court to hear a case about mass killings on foreign soil.
"There's also the question of to what extent we really want our federal courts to become basically the human rights police for the world," Vladeck said.
In 2005, a Truth and Reconciliation Commission was set up to identify serious violations of international law that took place during the country's two civil wars. The commission looked into the Lutheran church massacre and recommended that a new court be established to prosecute war criminals, according to the CJA.
"But nothing happened after that," Sarkarati said.
"A lot of the victims lost faith in government, lost faith in the rule of law," she said. "For them, they thought justice was never possible."
Read the complaint below.