Shoen said his wife and son were in the basement at 713 Logan, maybe 10 houses from the Logan Court Apartments where the standoff was occurring.
He said he told her to stay there to avoid any stray bullets.
The report of gunfire came after officers deployed a flash-bang device at about 2 p.m. A helicopter was on standby, as the drama unfolded.
The incident began at 7:35 a.m. when police were called to the complex at Logan and Gay Streets to handle a disturbance. While speaking with a resident, "a gunshot was heard from inside of the apartment building," Flanders said.
It wasn't clear who was shooting or where the shot came from, Flanders said. Police cordoned off the area and evacuated all persons.
Flanders said at 11:15 a.m., Pottstown officers and Chester Montgomery Emergency Response Team members began a systematic search of the B building and were able to figure out where the shots had originated.
As they negotiated with the man, the shots rang out at police from inside the man's unit in the B building.
The SWAT team is highly trained to respond to high-risk situations, including those of barricaded individuals.
At noon, Juli Burke, 44, who lives in the A building with her 8-year-old son, was told by Pottstown police to evacuate immediately.
Burke, in an interview, said residents of the C building had told her they could see the as-yet-unidentified gunman pacing back and forth in his ground-floor apartment living room in the B wing, still holding his weapon.
The apartment complex consists of four wings - A, B, C and D, Burke said. Each living room has a balcony and a big window.
At 8 a.m., Burke was cleaning the snow from her car in order to take her son to school, when she was approached by a police officer, who told her to go inside.
"It's a little nerve wracking to know that something as serious as this is going on," Burke said.
Contact staff writer Bonnie L. Cook at 610-313-8232 or bcook@phillynews.com.
Follow the Inquirer at www.Twitter.com/PhillyInquirer and www.Facebook.com/PhillyInquirer