To find out if anyone has ever died in your home, try asking the previous owners, landlord or neighbors, and search local newspaper records for your address. However, there is no reliable way to know for sure whether anyone has died in an older home.
Some states do require sellers and landlords to disclose recent deaths. The statute may be three to five years, depending on the state. However, this varies, so check your local laws. If you are buying a home, ask your Realtor about disclosure requirements in your state.
As of 2015, there is also a commercial service called DiedInHouse.com. This service allows you to enter your address and pay a fee, and it automatically searches a database of public and private records. However, it only covers digitized records, which means it may not be reliable for older homes.
If you are concerned about notorious or violent crimes in particular, these should be fairly easy to discover by searching newspaper records for your area. This can be done online or at a public library. Simply talking with people in the neighborhood may also be helpful. It may be better to ease into this question to get reliable answers.
It is a good idea to assume that most older houses, particularly those dating to the early 1900s or before, have had someone die in them. It was common for people to die at home in the past, and there may be no official records remaining.