Teen In Custody Over Explosives Left In Mailbox Bremante Bryant January 31, 2020 at 9:07 am in In The News - Morning Headlines, NEWS Tweet A seventeen-year-old boy is under arrest after police in Rockville found explosives in the mailbox of a Glen Park home. The owner of the home on Newgate Road called police Monday after discovering what the bomb squad later described as a modified firework. Police suspect that there may be others involved and that the teen in custody is connected to other crimes in the area. The investigation is ongoing. Tags: Mailbox bomb, Rockville explosives, Teen arrested in Rockville