The "coward or cowards' who killed rookie Shreveport, La., police Officer Chateri Payne, who was fatally shot Wednesday night, remained at large early Friday as investigators continued their search.

Acting police Chief Ben Raymond said a witness was detained for questioning after the fatal shooting but was later released. He did not say whether Payne's death was tied to a domestic dispute, as some media outlets have reported.

“At the early stage of the investigation, we are not willing to rule out anything,” Raymond said during the news conference. “We will follow every lead wherever they may take us, and we will work to identify and apprehend the coward or cowards responsible for the brutal murder of Officer Payne.”

“We will follow every lead wherever they may take us, and we will work to identify and apprehend the coward or cowards responsible for the brutal murder of Officer Payne.” — Acting Chief Ben Raymond, Shreveport, La., police

Payne, a rookie cop and mother, was shot at least four times – including once in the head – outside a home around 8:20 p.m. Wednesday and pronounced dead at a hospital less than a mile away, the Shreveport Times reported.

It wasn’t clear whether the house was hers. Authorities cited by the Times said a child was found inside the home but did not indicate whether the child was Payne's. Police Cpl. Marcus Hines told the Times that Payne was on her way to work a night shift when the shooting occurred.

Law enforcement officials gave a news conference Thursday in which they provided few details on the case.

"Many of her classmates were with us at the hospital, obviously having a difficult time with this," Raymond said at the news conference. "Though I did not know her well, she was a very professional officer, very fit, very intelligent. Her classmates spoke very highly of her."

Police have some information about a possible suspect but nothing certain enough to release, Raymond said.

"Since we're not sure exactly who the suspect is at this point, or suspects, we're going to assume that there's possibly suspects at large that could be armed," he said.

Paynes’s friends and family paid tribute to the fallen officer on social media.

Louisiana Gov. John Bel Edwards called Payne’s death “a tragic loss” for the Shreveport community and “for all of us who rely on police officers to keep us safe.”

Payne had graduated from the police academy in November – just two months before her death. In a Facebook post after her graduation, Payne wrote: “Long Days. Aching Nights. But I decided to stand tall on my dream. It is an honor to be able to join such a powerful family with my Brothers and Sisters in Blue.”

The November post has since received dozens of replies, with one reading: "So saddening. Sending my deepest condolences to the family. Rest in peace, dear one."

Payne's death came one day before another female cop -- in Davis, Calif. -- was shot and killed while responding to a traffic accident. A suspect in that case was later found dead by police.

Fox News' Dom Calicchio and the Associated Press contributed to this report.