Dallas authorities say the uniformed officer was "confronted" by Jean, pulled her gun on him and fired.
After the shooting, Jean was taken to the hospital and was pronounced dead upon arrival.
A Dallas Police Department officer shot and killed a 26-year-old man late Thursday after she entered his apartment in the Cedars believing it was her own, DPD said early Friday morning.
Jean graduated from Harding University in 2016, and he is remembered by classmates as a friendly, "all around great person" who always had a smile on his face. A blood sample was also taken from the officer to test for drugs and alcohol, according to Hall.
Jean was the son of Allison Jean, former Permanent Secretary of the Department of Education, Innovation and Gender Relations for St. Lucia, according to St. Lucia Ambassador Anton Edmunds.
The officer, who has not immediately been identified, has been placed on administrative leave during the investigation, NBC News reported.
Hall says the Texas Rangers will conduct an independent investigation. The patrol officer, described as a female Caucasian, has not been identified, but her name will be released when she is formally charged, Hall told reporters.
The unidentified officer remains in custody while the District Attorney's office and police determine appropriate charges, reports WFAA.
"We were dealing with what appears to be a very unique situation", Hall said at a Friday press conference, according to The New York Times. I've spoken with the Jean family, his sister, Alissa, specifically. "We understand the concerns of this community and that is why we are working as vigorously and as meticulously as we can to ensure the integrity of this case".
Jean moved to Dallas after college.
"He told me he had never heard the song before, but that day, he called back to St. Lucia and asked his grandmother to teach him that old hymn on the phone", Harding University President Bruce McLarty recalled in a statement Friday.
Jean worked at PricewaterhouseCoopers in Dallas, an global company that does assurance, tax and advisory work for companies around the world.
Jean was a graduate of Harding University in Arkansas and worked at PricewaterhouseCoopers, The Dallas Morning News reports.
"This is a awful tragedy", Jean's employer said. He was a risk assurance experienced associate. Family and friends have taken to social media to mourn the death of their loved one.