Too far out from your job description

LAST week I was standing with a crowd of mothers and children at the 9-Mile market in Lae when a police vehicle stopped where I was. We were ordered not to move while the policeman checked our pockets, bags and bilums.
A young man was apprehended by the police for reason.
He was not in possession of harmful drugs, under the influence of alcohol or had any firearm or weapon. He was badly beaten in front of the crowd, including his daughter.
He was put in the vehicle, which had knives and harmful objects.
There was a policewoman who uttered insulting words regarding the woman’s private part.
The man had some biscuits in his bilum and K60. The public contributed K50 and gave it to police on the promise to release him.
However, on their way they continued to beat him. The police got all the biscuits which he bought for his daughter including the K60, which is now a total of K110.
They released him at 5-Mile.
Is this the appropriate way for a case to be cleared – on the vehicle with a sum of money? Or is it cleared at the police station?
Is there any law to forcefully check innocent people’s belongings, even reaching into their pockets and bilums?
Was these part of the training they received or being instructed to execute?
I’m lost!

Observer
9-Mile (Menyamya Block), Lae