The person denies the crime.
"I cannot say anything about his age or about what relationship or involvement he may have had in the incident due to confidentiality," prosecutor Sara Malmhester told Mitt i Tyresö.
In March, an 18-year-old man was shot dead on a bus in front of several witnesses near several schools in Tyresö. The suspected shooter, a man in his 20s, has also been in custody since then.
