Swedish law??????

i have just recently moved to sweden my wife is a swedish gypsi and i just wanted to try and understand the law in sweden. wife my wifes culture it is hard to contact the police for any reasson because gypsies dont have faitrh in the police and i can understand why. my wifes brother abuses drugs and alcohol and has a gun. one night he got into a argument with his wife and threatend to kill himself the shot his gun twice in thier appartment he left and went to the pub with his gun got into a fight with a family friend in the pub try to shoot him but the gun jammed. my wife called the police and told them that she wants to be anonymous and told the police the where abouts of her brother and that he is a danger to him self and to others and he is under the influence of drugs.so the police went to pick him up at the pub and found the gun with him and him under the influance of drugs he was held for like 10 days. after coming out a few days later he had known that my wife hiis sister had reported him to the police. so what i want to know is has the police the right to share that infomation with him or his lawer because to my understanding that infomation is irrelivent who called. they found him with the gun. my wife called the police and the police had told my wife that there is no law in sweden that the lawer could not hear the tape. but the lawer is a family friend and can iddentify the voice on the tape as my wifes. then the police tells my wife that sometimes the people in the comunity have to take a stand. if that is the case then why have police we might aswell take the law into our own hands. can someone please explain to me how the police are protecting the public by giving out that info and what makes people want to come forward to report anything after this?????????