I think your best bet is to use your time in Highlands Ranch to investigate the many urban Denver neighborhoods to see whether you feel comfortable in them.
There is so much diversity out there, and everyone is different as to what makes them feel "safe" or where they feel "comfortable".
We for example bought an old home in the redeveloping Cole neighborhood (near Curtis Park and downtown). Some of our friends think we're geniuses, even pioneers, others think we're crazy for living in what is still a sketchy (we prefer to call it
vibrant) neighborhood for the time being.
And for example, you couldn't pay me to live in Cap Hill, as for me, it is just too dense, parking is too problematic, and even though that neighborhood is farther along the "gentrification" process than ours, it seems like there is just as much or more drugs, car vandalism, and car theft. Not that it's a bad place, it's just the city, and not my style.
So anyway, you need to find what urban neighborhood best fits your preferences, budget, etc. But there are plenty of neighborhoods like ours with plenty of homes that need responsible owners like yourself to buy, fix up, and take a vested interest in the neighborhood.
If you find yourself considering the Cole/Five Points/Curtis Park/Whittier neighborhoods and would like some additional info from a current resident, shoot me an email or check out my neighborhood blog:
http://coleneighborhood.net
Cheers,
BS