All IMO
I'm going to say something most likely unpopular. I think they already have the suspect in custody and have for some time (on other charges).
I think because they knew who the suspect was right away, they made their statement of: "targeted attack" and "no threat to the community." They later retracted because they needed time to build their case before they accuse someone of being a psychotic killer. I mean, you have to get it right.
Also, LE haven't put together much of a public safety campaign stressing the importance of locking up, walking in pairs, etc. The college did a little, but I don't remember LE drilling it in, I feel like if they were worried, they would include safety information in their near-daily updates (which they've never done) on their website:
News Flash
I think our suspect is local and possibly a dropout of either UI or WSU, male, 22-28, wannabe military, someone in his family is a Marine (or he wanted to be), has a prior offense (assault or SA charge). He also likes dogs (lol) as they were the only things that gave him consistent love growing up.