Zyion Houston-Sconiers, 17, Treson Roberts, 16, and Amancio Tolbert, 16, have been charged with first degree robbery and conspiracy, Lindquist said.
"Three of these defendants are charged as adults because of their age and seriousness of the crimes," Lindquist said.
Two others accused in the robbery, aged 13 and 15, were charged with the same crimes but as juveniles.
Police said the muggers took wallets, back packs and cell phones when they confronted parents and children between 8 p.m and 9:30 p.m. Halloween night. An 11-year-old victim also had a bag of candy taken from him, but Tacoma police Lt. Gerry Lerum said the thieves were "just taking anything that the victims surrendered."
One of the robbers was armed with a loaded .22-caliber handgun, Lerum said.
A police dog tracked them to a car near the intersection of S. 15th and S. Sprague Ave. where officers arrested the suspects. Police also recovered the stolen items and seized the masks and a gun used in the robberies.
All five charged Monday were expected to make their first court appearance Monday afternoon.