As a non-American I always find these tales of self defencive weaponary part baffling, part horrifying. For me, it would be inconceivable to ride packing a gun, blade or mace. (You hearing me, European members?)
Seriously, I love the states. Love, love, love. I've road tripped it several times, yes including big cities, spent a month last year living in rural VT, even visited New Haven and never ever felt unsafe or threatened, but maybe just got lucky. Has poverty, wealth equality, endemic racism or whatever root cause gotten so bad that members here routinely fear for their safety?
As the OP, I should add that I ride trails extensively all over the northeastern US. Of the two hundred or so I've tried, only a relative few are what I would call a safety risk. A very low percentage to be sure. Before riding any new trail, I always do a bit of research first. There are several internet sites out there such as Traillink.com, that post user reviews. Any negative rider experiences are usually posted and I tend to avoid these places.
The real danger is having a negative experience on a trail you've ridden many times before without incident. Such is the case I described above. Virtually all the places I've felt threatened in the past have been near poor or run down neighborhoods in urban areas. The thing that alarmed me the most is the Carpendale Trail is definitely not in such an area. It's sad that I have to add this otherwise peaceful & scenic spot to my "avoid" list.