Police said Wednesday that a 14-year-old Raeshawn Rivers has been arrested in connection with Bowers' death. He is being charged as an adult, police said. No further details were immediately available.
Adonay Dixon, 23, and John Childs, 20, were arrested and charged on June 11. During a hearing Tuesday, Dixon was denied bail.
Police found Arnesha dead in her northeast Baltimore home on June 7 after responding to a fire.
"The motive was evil," said Stanley Bradford, the head of Baltimore's homicide unit.
Police said Bowers was sexually assaulted in her home in the Westfield neighborhood of northeast Baltimore and then strangled to death with an electrical cord.
They say Dixon and Childs stole $40, an iPad and a laptop before setting the home on fire.
"Can you imagine leaving your child at home and two people come into her house hell-bent on death and destruction?" Bradford asked. "I can only imagine what the last moments of Arnesha's life were like. It must have been pure hell."
According to Baltimore police, the two suspects said Arnesha had been spending time with two men before they planned to rob the teen's home.
Arnesha's grandmother picked her up one day at Childs' apartment, police said, and Dixon followed the car home on a bike.
"They believed the house would contain items of value because Arnesha's grandmother has a job and owned two vehicles, and planned to break into the property and steal any valuables," police wrote in a report.
Police say the men entered her home the day of the attack knowing Arnesha's grandmother was at work and the teen was alone Dixon planned to put her in a chokehold while sleep, police said.
The pair entered through a basement window waking Arnesha up, police said. Dixon dragged her into the basement while Childs robbed the home.
According to police, Childs told detectives that Dixon and Arnesha were in the basement for 30 minutes before Dixon came upstairs saying they need to leave "because the house was on fire".
Police said Dixon told Childs the girl was dead before her body, as well as her bed and dresser, were set on fire in the basement.
They said a check on her phone shows a call between her and Dixon hours before she was killed.
Police said Childs confessed to the killing and burglary and implicated Dixon. Police arrested Dixon hours later.
It was not clear if Dixon had an attorney. An attorney listed in online court records for Childs could not be reached.
Arnesha was a junior at Baltimore City College High School.
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