Va'aelua said police executed several search warrants yesterdaywith the assistance of the Armed Offenders Squad, leading to the accused's arrest.
Several firearms were also recovered during the morning raids, Va'aelua said.
Two other people were also assisting police with their inquiries, he added.
Va'aelua said many police officers have worked on the homicide inquiry since Brown's death.
"[Yesterday's] arrest is pleasing and a great relief to achieve this result," the detective said.
"This has come about through some tireless work by the police team working on the case and assisted by information provided from the public, including anonymous reports via Crimestoppers."
The funeral for Brown, who was also known as Afa, was also held yesterday.