A terrorist seeking a Jewish community center in midweek means seeking women and children. Same pattern at a Los Angeles a few years ago.
I don't know if there's anything to this, at least in this case, but it's an interesting thought. Schools and community centers are often targets, and they're no softer than Synagogues, all these places have had security and/or guards for years because of the threat. If I can find a quick link or two, I'll post them, but in the mideast women and children have been acknowledged as superior targets as it kills not just a Jew, but future generations.
This was not at a Jewish community center (though it was erroneously headlined to be so in some media accounts). It was at the offices of a Jewish charity organization, which had sponsored a large pro-Israel rally days before the incident.