A man who allegedly tied up his boss and killed her brother had bragged about planning the event, a court has been told.
On Tuesday Noelene Stevens, who was allegedly held hostage by Matej Hoi Stung Vanko in April last year, gave evidence at a preliminary hearing into events.
"He said he researched and planned these things very well, referring to what was happening at the time," Ms Stevens told the court.
"It was a bragging type of thing.
"He was actually very calm and calculating," Ms Stevens said.
Ms Stevens worked at security firm Serco and was the supervisor of Vanko at a Darwin immigration detention centre.
She described how she was scared when a helicopter flew overhead while Vanko was inside her home.
"I felt he was going to shoot me because he pulled the gun out and pointed it at me," Ms Stevens said.
She was agreeing with whatever Vanko said to her, to appease him, and at one point he asked her to promote him at work.
Vanko, 36, faces a string of charges including murder, aggravated assault, depriving a person of liberty, using a firearm while unlicensed and cruelty to animals.
Under questioning from defence counsel Ian Read, SC, Ms Stevens admitted her brother, with whom she lived, had once had a drug problem and that Vanko found syringes in Mr Stevens' bedroom at her house.
On Monday the court heard from Ms Stevens' neighbour, who saw her standing handcuffed in his house after she had fled there.
The police were then alerted and after several hours came to the neighbour's home to offer assistance.
The hearing continues.