By Agence France-Presse
The officer, who police have yet to identify and has been placed on leave pending official charges, will face criminal charges for the fatal shooting, officials said Friday.
A racially-mixed crowd gathered near the crime scene for a candlelight vigil late Friday to honor the victim, identified as Botham Shem Jean, 26, an immigrant from the Caribbean island nation of Saint Lucia.
"We are here to express our outrage, and we are here to demand accountability," said Imam Omar Suleiman, an activist at the event organized by the Dallas-based Mothers Against Police Brutality group.
"If this was not an officer that pulled the trigger, this person would be in a jail cell tonight!" Suleiman said
Mourners carried signs with slogans that read "Have a trial when police kill" and "Where is justice when police kill us?"
Authorities are seeking to charge the officer with manslaughter. Dallas Police chief U. Renee Hall told a news conference that the shooting was "a very unique situation."
"We have ceased handling (the incident) under our normal officer-involved shooting protocol," the chief said, adding that the officer's blood was being tested for drugs and alcohol.
'Was in no wrong place'
The shooting took place late Thursday at the end of the officer's work shift. While still in uniform, she told authorities she mistakenly walked into Jean's apartment in an upscale complex near downtown Dallas.
Police did not yet know what interaction occurred between Jean and the officer. After the officer shot Jean, she called emergency services and told responding officers that she had thought she had entered her own apartment.
"Right now there are more questions than answers," Chief Hall said.
Jean had graduated from a private Christian college in Arkansas in 2016 and had since been working at the accounting firm PricewaterhouseCoopers in Dallas.
"It just still feels like a nightmare," Jean's mother, Allison Jean, told NBC News. "I wish I would wake up and find that it wasn't true."
Allison Jean -- who according to the St. Lucia Times has served for years in the island's government -- said the details of her son's shooting make no sense.
Her son "was in no wrong place at any wrong time. He was in his sanctuary, in the place where he called home. He didn't deserve this," she told NBC.
Jean's sister, Allisa Charles-Findley, said she needs "answers for my baby brother."
"Just last week I was thinking of what to get you for your birthday," she wrote on Facebook, "now I have to go pick out your casket."
Neighbor Alyssa Kinsey told The Dallas Morning News that Jean helped her move new furniture into her apartment soon after she moved into the building with her family in April.
"I'll remember his smile," she said. "It just lit up a room."