WAUKESHA, Wis. — The reserve police officer radioed in with an alarming report. Two people witnessed a fight, possibly involving knives, outside the Rotary Building at a riverfront park in Waukesha, Wis.
Within seconds, several officers said they would head there. The dispatcher told them to hurry. But when the first patrolman arrived, near the spot where kayaks are rented out in less frigid months, whatever fight might have happened was over.
“I’m by the Rotary Building and the baseball diamond,” the officer said, his voice calm. “There’s nothing here.”
About a minute later, panic crackled across the police scanner. The driver of a maroon S.U.V. was charging through the Waukesha Christmas parade on Main Street, not far from the park, barreling over marching band members and a troupe of Dancing Grannies. He wasn’t stopping.
The authorities in Waukesha accused Darrell E. Brooks, 39, of killing six people and wounding more than 60 others in the attack at the parade on Sunday evening. They said he had been fleeing a nearby domestic dispute that may have involved a knife — an apparent reference to the earlier incident at the park.
Mr. Brooks, who cried at the defense table in his first court appearance on Tuesday afternoon, was charged with five counts of first-degree intentional homicide and ordered held on $5 million cash bail. Prosecutors said they learned of the sixth death, of an 8-year-old boy, on Tuesday and intended to file another homicide charge.
“There are not words to describe the risk that this defendant presents to our community,” Susan L. Opper, the Waukesha County district attorney, said in court, where she referred to accounts by detectives who said Mr. Brooks had seemed to intentionally steer into people.
“He was told to stop by police officers,” Ms. Opper said. “They risked their own safety to try to step in front of the car to stop him. Everything was done to get him to stop — and he just simply continued down the roadway, causing death and destruction.”
Kevin Costello, the court commissioner who presided over the bail hearing, granted prosecutors’ request for the $5 million bail.
“It’s an extraordinarily serious case, with an extraordinary history of this gentleman — of fleeing, of hurting people, of not following court orders, not following criminal laws, not following just your societal norms,” Mr. Costello said.
A lawyer for Mr. Brooks said little in court, but told the court that his client was indigent. Mr. Brooks, who wore a dark green vest and white face mask, hung his head for most of the hearing.
On Tuesday, as some victims remained hospitalized, Waukesha residents were still trying to piece together what had happened in their usually calm downtown over the weekend. With public schools in the Milwaukee suburb closed again on Tuesday, flags flew at half-staff and buses displayed the message “Waukesha Strong.”
The police have provided only limited details about the attack, and did not respond to questions about whether the domestic incident Mr. Brooks was accused of fleeing was the fight reported at the park. No similar disputes were discussed in the minutes before the attack on a Waukesha police scanner feed published online by Broadcastify.
Greg Legate, who lives about half a mile from the end of the parade route, said he called the police on Sunday evening after coming upon a stranger, later identified as Mr. Brooks, standing on his next-door neighbor’s porch. Mr. Legate said he had just returned home from the parade, where he and his family saw an older woman hit by the S.U.V. fly into the air and land on the curb in front of them, apparently dead.
“I knew they were looking for somebody and figured it was the guy from the parade because that was the direction he was heading,” Mr. Legate said.
When he first approached his neighbor and Mr. Brooks, Mr. Legate sensed something was wrong. His neighbor, he said, whose doorbell camera recorded footage of their encounter, seemed unaware of the manhunt at the time.
“I didn’t care whether he was the guy or not,” Mr. Legate said, “it was my responsibility to call.”
Without uttering a word, Mr. Legate went around the corner in the dark to dial 911, standing behind his house. Mr. Brooks, he said, “was just looking at me funny.”
“When I went around the corner,” Mr. Legate continued, “he was looking around to see where I was going.”
To the dispatcher, Mr. Legate recalled saying, “The man that you are looking for, I believe, is at my neighbor’s house.”
Within a minute of the 911 call, he said, the police were there. Mr. Legate said he and his friends sat in their car and watched while officers took Mr. Brooks into custody.
“They were there with guns drawn and telling the man to put his hands up,” Mr. Legate said on Tuesday. “It was fast.”
Mr. Brooks, who did not speak in court, had been arrested in the Milwaukee area repeatedly over the years, accused at various points of battery and domestic abuse and resisting the police. Prosecutors on Tuesday spent several minutes describing his criminal record from several Wisconsin counties, as well as for a sex crime in Nevada, where there is an active warrant for his arrest, and a recent arrest in Georgia.
A woman who had a child with Mr. Brooks almost two decades ago said in an interview on Tuesday that his temper was easily ignited. The woman, who spoke on the condition of anonymity because she did not want herself or her child to be publicly associated with Mr. Brooks, said that she knew he had anger issues, but that he had never been abusive toward her.
Just a few weeks ago, prosecutors in Milwaukee County said Mr. Brooks intentionally ran over another woman he knew with a maroon Ford Escape.
Prosecutors said they had erred in recommending a $1,000 cash bail in that case. Mr. Brooks posted that bail, then was held in custody for a few days while awaiting transfer to Waukesha County for a warrant issued over unpaid child support. He was sent to the jail in Waukesha on Nov. 16 and released later that day after telling a judge he had missed the support payments because he had been jailed in Georgia.
Days after his release, on what had been a celebratory night, with a beloved parade returning from a pandemic hiatus and children lining the streets, Mr. Brooks was back in Waukesha. Police officers and prosecutors said he seemed to maximize damage as he rampaged through the parade route.
“It looks like there was either panic or whatever, or an intentional act for whatever reason,” Mr. Costello said. “You don’t do well under pressure.”
Shaila Dewan and Robert Chiarito contributed reporting. Kitty Bennett contributed research.