Without specific details about the event you are referring to, I cannot provide a direct answer to your question.
However, in general, law enforcement agencies may withhold certain information related to an ongoing investigation or criminal case to avoid compromising the integrity of the investigation. They may also withhold sensitive information to protect the privacy of individuals involved, such as victims and witnesses.
Releasing a manifesto written by a mentally ill individual involved in a crime raises complex ethical considerations. Publishing such content could potentially inspire others, glorify the perpetrator, or cause harm to those affected by the incident. Balancing the need for transparency with the potential risks is a delicate matter for law enforcement agencies and authorities.
If you are interested in the specific case you mentioned, I recommend checking reliable news sources and updates from law enforcement agencies to get the most accurate and up-to-date information.