I am a new investor, and am wondering if a home situated next to someone on the local sex-offender registry is enough of a red-flag to warrant letting this home pass, or is this something that can be accounted for when setting a target selling price? 

The only thing at the County level in MA is the Registry of Deeds, everything else is by town/city including property taxes.  

Search the registry of deeds and check out the existing mortgages too.

The law states the rent money must be paid to the court registry if the tenant intends to challenge the eviction, and it bought her enough time to find a social services agency to provide the money.

Joe GoreThat is why people promote the multi level entity stuff.Much harder to track down the "people" involved if title is held in a Trust where the beneficiary is an LP that has an LLC as the GP.Not impossible by any stretch but it is more than checking title at the registry and then going to the Sec of State to see the names on the corporate docs.

Building is on the historic registry.

Can I file something with the registry of deeds in my county stating that the property at X location owned by Mr Smith has agreed to sell on this date to me (Tenant).Thats it for now thank you all for your input, I live in Maine and dont know how the laws differ from state to state, but if you can lead me to water i will drink.David

I require adequate income proven by paystubs, plus I check the sex offender registry and run a criminal background check. 

You may be able to check if they appear in any public registries such as a list of sex offenders. 

Check out the registry of deeds and find out if the original owner's information is listed and contact them directly and ask him/her to ask his/her agent to do his/her job.Regards,Scott Miller