The district court in Norrköping said that Kolmården's former zoological head had responsibility for the work environment "within the scope of activity in the zoo."
The court also found a number of shortcomings in his job responsibilities with no regular investigations and risk assessments made in terms of working conditions.
The introduction course for new zoo keepers working with the wolves was ruled by the court to be insufficient and there were no written instructions on how the keepers should act in risky situations.
The District Court also said that there were shortcomings regarding the reporting of previous incidents and accidents in the wolf enclosure. The reasons for this have not been studied enough, it said.
The most serious shortcoming of all it said was to allow zoo keepers working with wolves to work alone inside the wolf enclosure. They had no opportunity to raise an alarm and call for help in an emergency.
The District Court concluded that the zoological head of Kolmården "disregarded what was incumbent on him under the Work Environment Act to prevent illness and accidents."
The court mentioned another event one year before the accident in which a zoo keeper encountered a life-threatening situation when she was working alone inside the wolf pen. The director knew about it, but nevertheless continued the practice of wolf keepers entering the enclosure alone. Therefore, the District Court said that he had been grossly negligent.
The fatal accident four years ago could have been prevented if the zoo keeper had not been alone with the wolves, the court said. Therefore it convicted the zooloical head of the park of occupational crimes including manslaughter.
The penalty will be a conditional sentence and a fine because it has been more than four years since the crime was committed.
The wolf attack happened just an hour after the Kolmården Wildlife Park opened its gates for the summer holiday season.
The 30-year-old female zoo keeper was alone in the wolf pen when the animals she had raised from puppies attacked and killed her.
The head of Kolmården at the time said that the zoo keeper had broken no rules by going into the pen alone and that wolves at the park are usually not aggressive.
It is customary for two handlers to always enter a wolf enclosure together at a Swedish animal parks. However, at Kolmården in 2012, the wolves who attacked had, as young pups, been fed with baby bottles and reared to meet visitors.
After the accident, the park decided to forbid visitors from entering the wolf pen to pet the animals.
The Kolmarden Wildlife Park was sentenced on Wednesday to pay SEK 3.5 million in corporate fines. The victim's siblings have claimed damages from the animal park director and the zoo. The court said that the victim's sister had a "particularly close relationship" to the keeper and that she was therefore entitled to damages
Kolmården is one of Sweden's most popular tourist attractions, with more than 500,000 visitors a year.