Atlanta police have made an arrest in Thursday morning's shooting death of a lounge owner who authorities said was scheduled to testify in an upcoming murder trial.

Otis Ricks, 23, was arrested at the Hotel Magnolia on Old Dixie Highway for the murder of Vanessa Thrasher, Atlanta police spokeswoman Kim Jones said Friday. More arrests are expected, Jones said.

Thrasher was scheduled to testify as "a very important witness" in a murder trial next week, Fulton County's chief prosecutor told Channel 2 Action News.

Thrasher, 53, of Lithia Springs, was the owner of O.T.'s Lounge Soul Food Grill at Joseph E. Boone Boulevard and New Jersey Avenue.

"We're working very closely with the Atlanta Police Department and with the U.S. Marshals Office and we're trying to figure out whether there's any connection between the trial and the incident that occurred last night," District Attorney Paul Howard said of Thrasher's killing.

Earlier Thursday, Atlanta police homicide detectives said they had developed some leads in the killing and released photos of three suspects.

In an interview Thursday night with Channel 2, Howard said that Thrasher was to have testified at the trial of William Perkins, who is charged with killing one of her employees, Jerome White, during a fight at the woman's bar in May 2011.

Perkins' accomplice, Lavanda Heard, recently took a plea deal in connection with White's death, the DA said.

"Yesterday, we did our final preparation with [Thrasher]," Howard said. "She left our office sometime after 4 o'clock. This morning, we were awakened with the terrible news she had been brutally murdered."

Howard said authorities were concerned for the woman's safety, had talked to her about putting her in protective custody and had arranged for police patrols to go by her place. Whoever killed her may have watched and waited for a break in the surveillance, he said.

The DA said he was determined to press forward with the trial.

"When people attempt to intimidate the criminal justice system, we're not going to stand for it. We're going to go forward with the case on Monday," Howard said. "We want criminals to understand that they cannot shut our criminal justice system down simply by removing witnesses from the ability to come into court and testify."

Howard urged anyone with information about the killing to contact police.

"We should get these guys behind bars immediately. We should send a very strong message that we're not going to let this happen in Fulton County," he said.

Anyone with information on the case was asked to call Crime Stoppers Atlanta at 404-577-8477. Callers can remain anonymous and may be eligible for rewards up to $2,000.

Atlanta police Capt. Adam Lee III told the AJC that around 2 a.m. Thursday, an officer was patrolling the area when he heard several gunshots.

That officer stopped a man who was leaving the lounge "in a panic," Lee said. "But as it turns out, that subject is claiming to be the victim of a robbery and a witness to the shooting."

"We later learned that while he was detaining that one subject who was claiming to be a witness, two suspects casually walked out and got into a car and left the area," Lee said. "They didn't run or cause any alarm [or give] any reason for the officer to believe that they were involved."

The officer then went inside and found the victim dead with at least two gunshot wounds.

"She appears to be a very well-liked person, and had been in the community for quite a number of years," Lee said. "I was told that that business has been in the community for as long as 50 years."

A large group of bystanders remained on the scene nearly four hours after the shooting, as detectives continued to gather evidence and interview witnesses.

Among the group was Tony Wise, who said the victim "had a good heart. She was a good person, period."

Wise told the AJC that her death was a "big loss" for the neighborhood.

"This place has been here since I was born," Wise said. "This was a family business. Her daddy used to own it and he passed away and left it to her."

Wise said the victim was known for her various hamburgers, some with bawdy menu names that can't be repeated on a family-friendly website.

"She could make the best hamburgers in town," he said.

—Dispatch editor Angel K. Brooks contributed to this article.