Spiny Assassin Bug

This spiny assassin bug had to endure a few minutes of me and my flashes after I spotted it sitting along a path at Darby Park today. I don't know what kind it is... but I found another similar one a few minutes later down the path... so it's probably a common breed. At first I thought it might be a wheel bug (a type of assassin bug) because of the spines along its head... but after looking for examples online I've concluded it's not a wheel bug.