The gunman, named as António Duarte, 40, walked into the Lagos office of the CPCJ just after 9am, and took three hostages, including an off-duty police officer, who were released unharmed shortly after 5pm.
Several SWAT teams and police reinforcements gathered at the scene while negotiations were ongoing.
António Duarte, a construction worker in Lagos, had demanded to speak to reporters to tell them his story after he lost custody of his children.
He had on previous attempts tried to tell his story to the media, but none of his approaches were accepted.
Speaking to The Portugal News at the scene shortly after the start of the hostage crisis, a local resident told of his terrifying ordeal as he came face-to-face with the gunman.
“I had a meeting at the institute this morning when I walked in I saw a man armed with a sawn-off shotgun”, Carlos Cordeiro from Lagos explained to The Portugal News.
“I realised something was amiss by the worried expressions on people’s faces inside the building. Among them was a man whom I recognised as being a GNR police officer, dressed in civilian clothes.”
The information about a policeman being inside the building was not disclosed until after the safe release of the hostages.
Carlos Cordeiro continued to reveal that when he walked into the CPCJ office, the gunman, who he said was “very calm,” approached and asked what he was doing there.
“I told him I had a meeting scheduled for that morning with one of the officials there. Upon seeing me, the person who I was supposed to meet told me to leave. She looked particularly distressed.”
Cordeiro added that in addition to the shotgun, the gunman was wearing a large coat in which he could possibly be concealing more weapons and ammunition, suspicions which he also passed on to police: Upon his arrest later that evening, police discovered the gunman was also carrying a 7.65mm handgun and dozens of rounds of ammunition.
According to Cordeiro the gunman had asked him whether he wanted to call the police.
“I didn’t reply to his question, and instead placed my 11-year old son behind me at which stage the door at the entrance closed.
“I turned around and walked towards the door and managed to leave. Above all else, I’m certain he let me go because I had a child with me”.
Carlos Cordeiro exited and called the police once he was out of the gunman’s sight.
“They were there within four or five minutes. One police officer went around the back, at which stage the man inside fired a shot through the window which resulted in what appeared to be slight facial injuries to the officer.”
Throughout the day, several curious bystanders gathered at the scene, with a large area cordoned off by police as a precautionary measure.
António Duarte has been remanded in custody pending trial, during which he is set to face charges that are likely to include the attempted murder of a police officer.