Nikolas Cruz jumped out of an Uber car and walked toward building 12 of the Marjory Stoneman Douglas High School, carrying a black duffel bag and a black backpack. A man inside the school spotted Cruz and knew he was a former student, a troubled kid. He radioed a co-worker, and within a minute heard gunshots.

The 19-year-old was wearing a maroon shirt, black pants and a black hat. The man, whose name was blacked out from a sheriff鈥檚 affidavit, told detectives Cruz was moving 鈥減urposefully.鈥�

Cruz slipped into the building, entered a stairwell and extracted a rifle from his bag, authorities said. He shot into four rooms on the first floor 鈥� going back to spray bullets into two of the rooms a second time 鈥� then went upstairs and shot a single victim on the second floor. He ran to the third floor, where according to a timeline released by the Broward County Sheriff鈥檚 Office, three minutes passed before he dropped the rifle and backpack, ran back down the stairs and quickly blended in with panicked, fleeing students.

Related:

Florida State Sen. Bill Galvano, who visited the third floor, said authorities told him it appeared that Cruz tried to fire point-blank out the third-floor windows at students as they were leaving the school, but the windows didn鈥檛 shatter. Police told Galvano that it was not that difficult to open the windows.

鈥淭hank God he didn鈥檛,鈥� Galvano said.

From the time Cruz entered the building until the time he left, only six minutes passed. During that brief time, he shot more than two dozen people, including 17 fatally.

After the rampage, he walked to a Wal-Mart and bought a drink at a Subway restaurant, then went to a McDonald鈥檚.

About 40 minutes later, a deputy saw him walking down a suburban South Florida street and grabbed him. He didn鈥檛 put up a fight.

The details of Wednesday鈥檚 carnage at the Parkland, Florida, high school emerged a day later from witnesses and law enforcement reports.

Related:

Among the dead: assistant football coach Aaron Feis, slain while shielding students from bullets; Joaquin Oliver, a student known for his unique look and who once dyed his hair bleach-blonde with tiger stripes; Alyssa Alhadeff, an avid soccer player and student; and 35-year-old geography teacher Scott Beigel, who helped students enter a locked classroom, only to be shot himself.

Among at least 1,000 people attending a candlelight vigil near the school Thursday night, some openly sobbed as the victims鈥� names were read aloud. At one point, people began chanting, 鈥淣o more guns! No more guns!鈥�

Dressed in the school鈥檚 red colour, some held flowers while others wielded signs asking for action to fight school violence, including gun control.

鈥淜ids don鈥檛 need guns. No guns under 21,鈥� read one sign.

Ernest Rospierski, a teacher at the school, took several bracing breaths at the vigil as he talked to a reporter about the horror in the halls.

鈥淏ang bang bang - all of a sudden the shooting stopped,鈥� he said. 鈥淚 looked down. He was reloading. I yelled run. And then I ran behind as many kids as I could.鈥�

Authorities have not described any specific motive, except to say that Cruz had been kicked out of the high school, which has about 3,000 students and serves an affluent suburb where the median home price is nearly $600,000. Students who knew him described a volatile teenager whose strange behaviour had caused others to end friendships.

Cruz was ordered held without bond at a brief court hearing. He wore an orange jumpsuit with his hands cuffed at his waist. His public defender did not contest the order and had her arm around Cruz during the short appearance. Afterward, she called him a 鈥渂roken human being.鈥�

Cruz was under a suicide watch, said Executive Chief Public Defender Gordon Weekes.

Wednesday鈥檚 shooting was the 17th incident of gunfire at a U.S. school this year. Of these, one involved a suicide, two involved active shooters who killed students, two involved people killed in arguments and three involved people who were shot but survived. Nine involved no injuries at all.

Related:

Officials were investigating whether authorities missed other warning signs about Cruz鈥檚 potentially violent nature.

He had been expelled from the school for 鈥渄isciplinary reasons,鈥� said Broward County Sheriff Scott Israel, who said he did not know the specifics.

One student said Cruz had been abusive to his ex-girlfriend and that his expulsion was over a fight with her new boyfriend.

Two federal law enforcement officials said the Smith & Wesson M&P15 .223 was purchased legally at Sunrise Tactical Gear in Florida.

Cruz passed a background check and legally purchased the assault weapon in February 2017, a law enforcement official familiar with the investigation told The Associated Press. The official was not authorized to discuss the information publicly, and spoke on condition of anonymity.

__

Lush reported from St. Petersburg, Florida. Associated Press writers John Mone and Sadie Gurman contributed to this report.

Kelli Kennedy, Curt Anderson And Tamara Lush, The Associated Press

Like us on and follow us on .