Two other officers, Nathan Bettencourt and Nicholas Kasper, also were injured in the shootout with James Waters, 37, according to the state patrol. A SWAT team later found Waters dead inside the home.
The three Clinton Police Department officers, however, shouldn't have been sent to the Clinton address because the 911 call originated from an address in nearby Windsor, Missouri, Sgt. Bill Lowe of the highway patrol said Wednesday during a news conference.
The 911 request was "somehow attached" to the Clinton site, which is about "14 or 15 miles" away from its origin in Windsor, Lowe said.
"As (for) the 911 call that came in, we were later able to determine that it was not from that residence in which they were responding to," Lowe said.
A computer system traced the call -- during which no one spoke directly to a dispatcher -- to Clinton instead of Windsor, Lowe said, adding that he could not speak to specifics about the call system.
Investigators by Wednesday had spoken with people involved in the 911 call and were confident they had nothing to do with the deadly shooting in Clinton, he said. The women acknowledged they'd argued and called 911, but that call was unrelated to the Clinton shootout, Missouri Highway Patrol spokesman Sgt. Collin Stosberg said Thursday.
The address error was likely due to a glitch in the 911 call technology, Stosberg said, though he did not elaborate.
The mistake will be investigated as part of an ongoing probe by the highway patrol, the Henry County Sheriff's Office, the county's prosecutor and the Clinton Police Department, Lowe said.
Officer at scene asks about 911 call
After dispatchers got the 911 call, officers were sent to the home in Clinton. Tammy Widger, 37, opened the door and told them there wasn't a problem and she was home alone, Stosberg said.
Following protocol for responding to 911 calls, the officers entered the home to make sure everyone was safe, Stosberg said. That's when Waters, who had been near the back of the home, opened fire.
Morton, Bettencourt and Kasper returned fire, and Morton was killed, Lowe said.
In dispatch audio of the shooting obtained by CNN from scanner streaming service Broadcastify, an officer can be heard asking a dispatcher what was heard on the 911 call.
"We can just hear two females arguing," the dispatcher responds. "We're not sure what they were saying."
A short time later, an officer can be heard saying, "Shots fired." Morton, who sounds out of breath, tells dispatchers he's in a back room of the home.
An officer asks Morton if he's OK, and he says no, that he's been shot in several places.
Bettencourt and Kasper were treated for bullet wounds -- one in an arm and the other in a shoulder. Kasper was released Wednesday from a local hospital, and Bettencourt on Thursday was in stable condition, recovering from his wounds and surgery at a hospital in Kansas City, according to the highway patrol.
An autopsy will determine whether Waters shot himself or was killed by police gunfire, Lowe said.
Shooting overlaps other cases
Waters had been on the Clinton Police Department's radar in connection with an alleged rape, Lowe said, adding that the rape claim is not related to the shooting.
Indeed, Clinton officers had tried to contact Waters on Tuesday about the rape case, Henry County Prosecuting Attorney Richard Shields said. Shields did not say whether the parties spoke.
Waters was known to be associated with the Clinton address, Stosberg told CNN on Thursday. Henry County authorities earlier Tuesday had tried to serve him a warrant in connection with the rape case.
Waters' daughter, Lakeviona Waters, told CNN affiliate KSHB
that her father suffered from bipolar disorder and schizophrenia.
"Something was really going on with my daddy," she said. "And only if I would have reached out to him, then I wouldn't have had him believing that I really hated him. I don't think he would've did it."
Separately, Widger was charged Wednesday with possession of methamphetamine with intent to distribute and keeping or maintaining a public nuisance, alleging she had sold drugs from the home in the past, Shields said. She is in custody with her bond set at $25,000.
"At this point, there's really no clear correlation" between the shooting and Widger's alleged drug distribution, Shields added.
Morton 'took his place' after a comrade was killed
Morton died seven months to the day another Clinton officer was killed.
Officer Gary Michael, 37, was gunned down during a routine traffic stop after pulling over a vehicle for a suspected registration violation.
Morton had been with the Clinton Police Department for at least three years when he became a reserve police officer, Lowe said. But when Michael was killed, Morton "felt a calling to come back to the police department in a full-time capacity and applied to be a road officer again."
"Did he take his place? Absolutely, he took his place," Lowe told reporters. "The police department has endured a lot over the last seven months, and then to endure it again -- it's going to be difficult for them."