Updated at 5 p.m. April 15: Revised to include information from a news conference.

Police say a man who is accused of attacking a transgender woman Friday in east Oak Cliff was offered $200 to beat her.

Edward Dominic Thomas (Dallas County Sheriff's Dept.)

Edward Dominic Thomas, 29, was arrested about 9:30 p.m. Sunday on a charge of aggravated assault causing serious bodily injury, two days after the attack, which was recorded on video.

Police Lt. Vincent Weddington said Monday that the case is being investigated to determine if it meets the criteria of a hate crime and that the department has contacted the FBI.

The victim told police that she accidentally backed into another vehicle while driving in the Royal Crest Apartments parking lot in the 3500 block of Wilhurt Avenue between 5 and 6 p.m. Friday.

The driver of the other vehicle, who is named as a suspect in Thomas' arrest warrant affidavit but has not been arrested, said he ran the victim off the road to keep her from fleeing.

The victim, Muhlaysia Booker, told police the other driver pointed a gun at her and refused to let her leave unless she paid for the damage. As a crowd gathered, someone offered Thomas $200 to beat Booker, the affidavit said.

Video of the incident showed that Thomas put on gloves, then walked over to Booker and punched her multiple times.

Police say another suspect who has been identified but not arrested repeatedly stomped on Booker's face.

Several women carried Booker to a car and took her to UT Southwestern Medical Center, where she spoke to officers and said homophobic slurs were used during the assault, police said. She suffered a concussion and a fractured wrist, as well as bruising and swelling to her face.

Police are reviewing audio and video recordings to see how many people were involved in the beating and who, if anyone, offered Thomas money to beat Booker, Weddington said.

He said police expect to make more arrests in the case.

"This case is certainly disturbing," Weddington said. "The video, I'm sure, shocks the conscience of anyone who looks at this video. ... This is being taken very seriously in our department."

Unnamed people told Booker that Thomas had been one of her attackers, and a Dallas officer who encountered Thomas after the assault recognized him later after viewing video of the incident, according to the affidavit.

Police found Thomas in the bathroom of an apartment in the 3300 block of East Illinois Avenue on Sunday. An officer told him he was not under arrest, and during an interview he admitted to the assault but not to "saying anything derogatory" about Booker, the affidavit says.

Thomas remained in the Dallas County Jail on Monday morning, with his bail set $75,000.

Thomas has previous convictions in Dallas County for family violence assault, burglary and unlawful carrying of a weapon.

Anyone with information about the case is asked to call Detective Christopher Evans at 214-671-3584 or email christopher.evans@dpd.ci.dallas.tx.us.

Staff writers Tom Steele and Sarah Sarder contributed to this report.