Dayton, Ohio(CNN) The Ohio gunman who ripped apart nine families in almost an instant managed to fire 41 shots in less than 30 seconds, police said Monday.
He did so by wielding a .223-caliber high-capacity rifle with 100-round drum magazines.
"It is fundamentally problematic," Dayton Police Chief Richard Biehl said. "To have that level of weaponry in a civilian environment, unregulated, is problematic."
Nearby patrol officers quickly gunned down suspect Connor Betts within 30 seconds after his first shot early Sunday morning, Biehl said.
But by then, Dayton's popular Oregon District was already the scene of widespread carnage.
Nine victims, including the gunman's sister, were pronounced dead at the scene around 1 a.m. Sunday.
"It seems to just defy believability that he would shoot his own sister. It's also hard to believe that he didn't recognize that that was his sister," Biehl said.
Another 37 people were injured, Dayton Fire Chief Jeffrey Payne said. Of them, 14 were struck by gunfire, and others were injured while trying to escape, Biehl said.
Surveillance video shows the shooter targeting people enjoying a Saturday night out in Dayton's Oregon District.
As gunshots rang out, people ran into nearby bars and clubs. Just before Betts was able to enter a nightclub, police gunned down the shooter.
"The officers immediately advanced toward the gunfire and within approximately 20 seconds, they engaged the suspect, who was actively firing and attempting to enter a crowded liquor establishment," Biehl said.
"The threat was neutralized at approximately 30 seconds of the suspect firing his first shot."
But the devastation was already done. Investigators found 41 spent shell casings from Betts' weapon, the police chief said.
Biehl said if all the magazines were full and at full capacity, the shooter may have had up to 250 rounds in his possession at the time.
Dayton Mayor Nan Whaley said police officers' handguns are no match for a weapon like the one Betts used.
"I really don't understand why a gun of that magnitude is really needed on the streets ... while our officers have handguns and shotgun rifles to go back at it," Whaley told CNN Monday.
"I think it begs the question: What are we doing?"
Nine states, plus the District of Columbia, ban large-capacity ammunition magazines. Ohio isn't one of them.
The nine states are California, Colorado, Connecticut, Hawaii, Maryland, Massachusetts, New Jersey, New York and Vermont, according to the Giffords Law Center to Prevent Gun Violence.
Among the states that ban high-capacity magazines, some prohibit magazines that hold more than 10 rounds, and others ban magazines that hold more than 15 rounds.
In Ohio, Whaley emphasized that just a few seconds of shooting led to nine deaths.
"I really want to think about that minute," she said. "The shooter was able to kill nine people and injure 26 in less than a minute."
The city of Dayton identified the nine people killed in the shooting:
-- Lois L. Oglesby, 27
-- Megan K. Betts, 22
-- Saeed Saleh, 38
-- Derrick R. Fudge, 57
-- Logan M. Turner, 30
-- Nicholas P. Cumer, 25
-- Thomas J. McNichols, 25
-- Beatrice N. Warren-Curtis, 36
-- Monica E. Brickhouse, 39
Relatives of the victims are grappling with both grief and bewilderment as to why their loved ones were killed.
While the motive remains a mystery, more disturbing details about the shooter are emerging.
Authorities searched the Betts' family home in Bellbrook, a suburb southeast of Dayton, and uncovered writings that expressed an interest in killing people, two law enforcement sources told CNN.
But the writings did not indicate any racial or political motive, sources said.
Former schoolmates said they were on a "hit list" Betts created back in high school. One described Betts as "dark and depressive."
One former classmate, who was told by a school official that he was on the alleged hit list, said the list was separated into two columns: a "kill list" for boys and a "rape list" for girls.
Biehl cautioned against drawing conclusions from any such list, or statements by others about the shooter's previous behavior. Biehl said that while authorities are exploring every piece of information, he was "reluctant" to interpret information from a decade ago as an indication of what happened on Sunday.
"We really don't know until we have all of the information, all of the evidence available," he said.
Megan Betts, the sister of the suspect, was one of the nine people killed.
Police did not detail the Betts siblings' relationship. But they did say that the two arrived together but separated at some point.
Biehl said the shooter killed his sister and wounded his male companion.
Authorities said they don't think the male companion, who had driven to the scene with the shooter and his sister, had advance knowledge of the attack, two law enforcement sources told CNN.
Bellbrook Police Chief Doug Doherty has been in touch with Betts' parents, who are not ready to talk about the deaths of their two children, Doherty told CNN affiliate WLWT.
"They are victims, and we're treating that as such -- them as victims," he said.