A torrent of anger threatened to derail a town hall forum Saturday that was designed as a call to action and discussion on justice for Botham Jean, the man slain in his own apartment by an off-duty Dallas police officer.

"This matter is bigger than any one of us," said the Rev. Richie Butler of Dallas' St. Paul United Methodist Church, where people gathered for the contentious and ultimately chaotic event Saturday, which would have been Jean's 27th birthday.

The Caribbean native was fatally shot Sept. 6 by an off-duty police officer who said she mistook his apartment for her own.

Amber Guyger was charged with manslaughter several days after the shooting and has been fired from the Police Department.

But activists say that the department was too slow to act and that Guyger should be facing a murder charge. As the panelists on Saturday urged patience to let the judicial process play out, the crowd's anger intensified.

The tenor of the event might have been most accurately summarized in the way it ended, with Butler's closing prayer drowned out by the chants of others: "'What do we want?' 'Justice!' 'When do we want it?' 'Now!'"

Things hadn't started that way. Early on, the crowd of about 200 heard from Jean's soft-spoken mother, Allison Jean, who called from St. Lucia to thank the community for its support and to declare her commitment to ensuring justice was done.

Melissa Perry (far left) shouts at Dallas County District Attorney Faith Johnson, who is seated next to Dallas attorney Justin Moore, regarding a question about Amber Guyger's charge, during a town hall panel regarding action taken following the death of Botham Jean, who was shot and killed by fired Dallas police officer Amber Guyger, at St. Paul United Methodist Church in Dallas on Saturday, Sept. 29, 2018. (Rose Baca/The Dallas Morning News) (Rose Baca / Staff Photographer)

"This is a difficult time for our family," she said, noting that vigils in her son's name were also being held in such cities as Atlanta, New York, London and Toronto. "Let us not rest until justice prevails. This is an international affair. The entire world is watching."

Pastor George Mason of Dallas' Wilshire Baptist Church said Jean's killing, and the wave of emotions that followed, have unveiled the depths of division and distrust between law enforcement agencies and the community.

"It didn't create something," Mason said. "It revealed something. And we will not have change until those who are unaffected by crime are as outraged as those who are."

As the panel of five — Dallas County District Attorney Faith Johnson; State Sen. Royce West, D-Dallas; activist Dominique Alexander; attorney Justin Moore; and McKinney City Council member La'Shadion Shemwell — began to take questions, the brewing anger began to boil over the lack of a murder charge and the failure of the Dallas Police Department to field a representative at the meeting.

Dallas Police Chief U. Renee Hall had been scheduled to appear Saturday but canceled because of a family illness, organizers said. Instead, many in the crowd took out their wrath on Johnson, the district attorney.

"Are you going to take that to a murder charge or not?" some shouted. Her attempt to explain the intricacies of the judicial process was met with skepticism and impatience — and Shemwell himself described it as "10 wasted minutes."

"We don't trust the Texas Rangers' investigation," he said, revving up big portions of the crowd. "We don't trust the Dallas Police Department's investigation."

Overall, it was not a group that wanted to be told to direct its outrage toward civic duties such as jury service or voting, as West and attorney Ben Crump had urged. Eventually, many who had been shouting objections from the rear of the church approached the panelists to confront them directly as moderator Roland Martin, a broadcast journalist, tried to keep them back.

"Y'all can back up, please," Martin said. "There are way too many folks up here."

And so it went. Calls to extend the session an extra hour were denied, and Butler called for a closing prayer, only to be outshouted by protesters as he began.

As attorney Daryl Washington had said earlier, "We want justice. But if we're not willing to step out of our comfort zone, we're not going to have any change."