I can see you have already had lots of answers to your question, but I will chime in with my two cents anyway. Summerlin is an extremely popular community and considered by many to be one of the best in the Valley.
That being said, as agents we are not supposed to "profile" different areas of town as safe or unsafe. But we can provide you with the Las Vegas crime statistics web site so you can draw your own conclusions.
It's pretty cool once you get used to how it works. To start, simply enter a property address at the top to search. When that specific property's area map opens, you can adjust the criteria by using the tabs above the map for crime types, dates, etc. The date will only go back for the past six months, but if you use the same criteria consistently it will give you a great idea of how much relative crime there is within a certain radius of a given address.
I like to search by zip codes myself. You can plug in the address as "89138, Las Vegas, NV" and pull up everything within a mile radius.
If you are truly concerned about crime, you may want to locate lower crime zip codes first and then look for homes within those zip codes rather than looking for a home first. You can go to this site and search for homes by zip code:
If you have any other questions, just let us know. We have been agents here more than 30 years, so we should have the answers. :)
Hope this helps!
Prudential Americana Group Realtors
The Tonnesen Team - with over 30 years of experience helping families call Las Vegas "home!"