Updated at 1:25 p.m. Friday: Revised to include a second arrest in the attack and details about the investigation.

Two brothers have been arrested in a brutal beating on a DART train that was caught on cellphone video last weekend.

Jakobi Darion Hendrix, 21, was taken into custody Thursday and was transferred to the Dallas County Jail late that night. He faces a felony assault charge in the attack on 44-year-old Kennan Jones.

Jakobi Hendrix (Dallas County Jail)

His older brother, 23-year-old Remon Hendrix, was arrested by Dallas police and booked into the jail early Friday, charged with a misdemeanor assault charge, Dallas Area Rapid Transit officials said. He also faces a theft charge.

Police say the Hendrixes were given away by the shirts on their backs.

Seeing that two of the attackers in the video were wearing Whataburger shirts, two detectives went to the restaurant on Haskell Avenue, where the brothers work. A manager there identified Remon and Jakobi Hendrix as the men in the video, according to police records.

On Thursday, the detectives watched surveillance footage of the brothers arriving at work about 12:40 a.m. Monday, shortly after the attack, with the same skateboards that were used in the assault, records show.

At about 2:40 p.m. Thursday the detectives received a call that Jakobi Hendrix wanted to turn himself in. His account of the beating differed from the victim's, however.

According to a police report, while on their way to work at Whataburger, Jakobi and his brother saw a commotion as their train arrived in Deep Ellum. They then saw another brother fighting a man "so he [Jakobi] jumped in to protect him," the report said.

Jakobi also said that "at one point the victim hit his brother [Remon]." After that, Jakobi said, they began assaulting the victim again, and he hit Jones with his skateboard.

The arrests come days after the cellphone video showed several young people beating a man on a Green Line train stopped at the Deep Ellum Station.

"We have identified some of the suspects responsible for the attack and are still working on identifying the others," DART spokesman Mark Ball said. "Our investigations will continue until we have identified and arrested those involved."

Remon Hendrix (Dallas County Jail)

In response to the attack and other worries about crime on trains and buses, DART police stepped up patrols at Deep Ellum Station and the station at nearby Baylor University Medical Center.

"In addition to DART PD actively patrolling the other stations, we are engaging our 13 municipal partners to provide additional patrol coverage to all 64 stations," Ball said.

Kennan Jones said the confrontation started when he asked the group to stop smoking pot on the train, KXAS-TV (NBC5) reports.

The cellphone video that's about 2 1/2 minutes long starts on the northbound train as the group punches and kicks a man. The fight then moves to the platform.

When Jones ends up on the ground, at least two of his attackers hit him with a skateboard as the others keep throwing punches. He's last seen lying limp on the platform as the mob scurries back onto the train.

Authorities suspect about five males and two females participated in the beating, which occurred about 11:30 p.m., Ball said.

Jones was taken to a hospital about midnight. A GoFundMe page has been established to help with his medical bills.

"We are also seeking any donations of transportation for Mr. Jones as we feel at this time it is unsafe for him to utilize public transportation in the Dallas area provided by DART," a statement from his family says.

DART police initially used surveillance footage from the platform to investigate the attack. They became aware of the cellphone video Tuesday morning, Ball said.

Littmobtv, a company that shares videos from around the world, posted it to Facebook about 7 a.m. Tuesday. It had been viewed nearly 189,000 times by Thursday night.

Anyone with information on the beating can contact DART police at 214-928-6300.

Staff writer Claire Z. Cardona and Breaking News editor Matt Peterson contributed to this report.