Video (04:22) : Surveillance video from the St. Cloud mall attack on Sept. 17 shows Dahir Adan attacking people with a knife and his encounter with an off-duty officer.

– Before he took up his knives, Dahir Adan delivered a haunting farewell — and warning.

“You won’t be seeing me again,” the 20-year-old Somali refugee told a SuperAmerica clerk as he stepped out into the night of Sept. 17.

An hour later, Adan was dead, shot down by an off-duty police officer after Adan hacked and slashed his way through the Crossroad Center mall with a steak knife in each hand. Ten people were stabbed and left bleeding, an entire community was terrorized.

At a news conference Thursday, investigators spelled out in detail just what happened in the mall that Saturday night, even as they still search for the reasons why. While they have yet to establish a solid link between Adan and a terrorist group, they said victim and witness interviews, store video, and Adan’s words and actions in the minutes before and during the stabbings pointed to a premeditated attack.

Authorities pulled out detailed maps, with red dots marking the spots where each person was stabbed: one dot for the pregnant woman in the parking lot; two for the father and son Adan ran down in the hall; another for the clerk he chased in the electronics store, demanding to know whether his victim was Muslim as he stabbed at him so hard that the knife bent on impact.

There were videos from mall surveillance cameras, showing Adan, dressed in his security guard uniform from work, chasing terrified shoppers. A quick-witted clerk in a candy shop slammed down the security grate just as Adan lunged toward him, knives clearly visible in his hands.

A frame grab from surveillance video taken of the St. Cloud mall attack shows Dahir Adan, right, using a knife to attack a mall worker at the beginning of his rampage.

The final moments of Adan’s life were captured on camera, from many angles, as he repeatedly charged off-duty police officer Jason Falconer, who was in the mall shopping. The videos show Adan lunging, falling, advancing again and eventually crawling across a bloodied floor toward Falconer with six bullets in his body and a knife still visible in his hand.

Sullen and withdrawn

It was only recently that Adan’s once-promising life veered off-course, FBI Special Agent in Charge Richard Thornton told reporters Thursday.

“Almost overnight,” Thornton said, Adan changed from a bright college student interested in basketball and video games into a sullen, withdrawn young man with an intense interest in Islamic studies. He went from top grades to flunking out of school. He lost weight, lost interest in his old pastimes and started chiding the young women in his family to be more devout.

It added up to a pattern that suggested to the FBI that Adan “may have been radicalized,” either on his own or with the help of others. Investigators have spent the past 19 days interviewing more than 180 people who knew him, viewing hundreds of hours of video and tracing his digital footprints and trying to unlock his phone, hoping to find where the pattern began.

“An increased interest in Islam is not, in and of itself, evidence of radicalization,” Thornton said. “But when combined with the other indicators and Adan’s violent rampage ... one could reasonably conclude his actions were consistent with the philosophies of violent, radical Islamic groups.”

The Islamic State claimed credit for the attack within hours of Adan’s death. The latest issue of an ISIL magazine, Rumiyah, published earlier this week, mentioned Adan’s attack in a roundup of recent “Operations” executed around the world. It referred to Adan as a “soldier of the Khalifah,” or caliphate, who carried out his attack “in response to the calls to target the citizens of the nations involved in the Crusader coalition.”

The article included a photo of ambulances stationed outside the mall. The Minnesota stabbing was the only American attack referenced, despite high-profile incidents in New York, New Jersey and Washington state last month. In the magazine’s English version, a two-page “exclusive” details how to carry out knife attacks, down to suggesting which knives to avoid.

“It is explicitly advised not to use kitchen knives, as their basic structure is not designed to handle the kind of vigorous application used for assassinations and slaughter,” the article reads.

Shooting justified

While authorities Thursday laid out many of the details of Adan’s attack, they also cleared Falconer of any wrongdoing in Adan’s death.

Falconer acted swiftly and appropriately after he found himself face-to-face with a knife-wielding man who demanded to know if he was a Muslim, Stearns County Attorney Janelle Kendall said.

Falconer, a former police chief who owns a local shooting range and works part-time as an officer for the Avon Police Department, told Adan “No,” he wasn’t a Muslim. After Adan turned and left, Falconer, who was off duty and in plain clothes, drew his weapon, identified himself as an officer and followed Adan, shouting at him to drop his weapons.

Several times Falconer showed his badge to reassure shoppers who were frightened by the sight of a man in plain clothes who was pointing a gun at a man dressed as a security guard, Kendall said. The chase led to Macy’s, where the cameras captured Adan as he repeatedly lunged at Falconer. Kendall said the clerks and shoppers in Macy’s heard Falconer identify himself again and again as a police officer and order Adan to drop the knives.

Before sharing the graphic details of Adan’s final hours with the public, investigators shared them with his stunned and grieving family. The family “cannot reconcile their view of a loving son with what has been presented by law enforcement,” said their attorney, Abdulwahid Osman.

There had been rumors in the community that Adan might have been provoked, or that there might have been a confrontation at the mall that sparked the attack. But investigators described a much more calculated buildup, beginning at 3 p.m. that Saturday, when Adan came home from his job as a security guard and didn’t remove his uniform. He told his family he had work to do that evening, but later texted his boss and told him he wouldn’t be coming in.

St. Cloud mayor Dave Kleis offered an update on the St. Cloud mall stabbing on Thursday.

Adan made his final trip to the gas station, delivering his ominous farewell to the clerk, just before 8 p.m. He returned home briefly, then headed to the mall, just minutes away. Along the way, he hit a cyclist hard enough to send the rider rolling across the hood of his car, but Adan never stopped. Investigators later found the cyclist’s glasses lodged on the car hood.

Adan then ran a red light before pulling into the mall’s south parking lot at 8:13 p.m. A minute later, St. Cloud fielded the first 911 call from the mall. Ninety-three more would follow.

Reporter Stephen Montemayor contributed to this report.

jennifer.brooks@startribune.com 612-673-4008

faiza.mahamud@startribune.com 612-673-4203

p.walsh@startribune.com 612-673-4482