The policewoman's actions, that she knelt with the demonstrators and held a sign with the text "white silence is violence" has aroused debate and was reported by several people.
None of the cases has led to a preliminary investigation, as it is not considered to fall under public prosecution.
However, it has been investigated internally by the police group for separation and discipline.
The decision is that the police violated their obligations regarding impartiality and risked upsetting trust in the police service, but that it is to be regarded as a minor offense, says Anna Westberg, press spokesperson at the Stockholm Police.
In view of the circumstances and the vulnerability that the policewoman was in, the investigation considers that it is a minor offense that is not a reason for a disciplinary sanction.
TT has sought Gunnar Edeland, head of the group for arbitration and disciplinary matters, who declined to comment further on the decision.