Police are investigating a rash of South End stick-ups targeting the area's nightlife.
The muggings began in July and occurred on or near Tremont Street, between East Berkeley Street and Massachusetts Avenue.
On Aug. 14, the Boston Police reported six robberies in a one-month period.
Captain Paul Ivens, commanding officer of District D-4 in the South End, believes the same person is behind all the muggings. All of them involved a man with a handgun, and most occurred between 2 a.m. and 3 a.m.
Witnesses have described the suspect as a 5-foot-8-inch black man in his 20s, but reports about his height and build vary.
"It's a crime of opportunity," Ivens said. "Unfortunately, he comes up from behind, and people really don't get a good look at him."
Ivens said the police have done a sketch of the man based on one victim's description, but they aren't releasing it publicly.
The seventh robbery, on Sept. 4, occurred on the corner of Shawmut and Milford streets around 2 a.m. Alexandra Hall, a Boston Magazine lifestyle editor, said she was with a friend and trying to hail a taxi, when the suspect approached.
"He basically sort of waved his gun in front of us and I handed him my bag," she said. "It had my iPad, my iPhone, passport and car keys. And my Invisalign, which nobody can use but me, but I need."
Hall was the first female victim. She had not heard about the previous incidents.
"I'm very cautious about personal safety," she said. "I don't walk alone at night, and I'm particularly wary in neighborhoods known for crime—at any time of day."