An odd statement. What is it about your family and friends that would endanger them if the facts about the sniper were made public?
In addition, suspicion of all foreigners will grow astronomically, and no doubt a few will be assaulted or killed. The hysteria will spread to the Black Community, which will have Black Muslims harrassed.
Some members of the black community, enraged by this, would no doubt retaliate in kind. Riots would break out in the black, Arab, and Hispanic areas, fueled by hot-shot vigilantes who think they are going to solve this crime.
Meanwhhile, the sniper would still be shooting people, and LE would be distracted by the increase in civil unrest.
If it were my city, I would not want all the information released either.
Also, some of the information might be EVIDENCE which would be compromised if released to the public.