Barnstable County was part of the original Plymouth Colony, and was officially founded in 1685. Needless to say, there is a great deal of history in this area and Barnstable County public records can be found going back much farther than in most U.S counties.
Given the long history of the county, you will have more than one place to look for Barnstable County public records depending on what year you are researching. Recent records from 1921 until the present can be ordered from the state Registry of Vital Records and Statistics in Dorchester. You can place an order by mail or visit the registry office during typical business hours. The local county clerk in Barnstable (the city) may also have the records you seek, and they will issue copies by mail or in person as well.
Mailed applications can take about a month to get back to you , unless you add on an extra fee for express service that will have your Barnstable Public records back to you in a week. When you visit the office yourself, then you can get them while you wait.
For records that fall between 1841 and 1921, you will have to look to the State Archives in Boston for access to those records. They have substantial holdings of Barnstable County public records that can be searched in-person but they will also do some research for you for a small fee. Many collections have online indexes where you can search to find out more about the records you need.
Finally, any records that are from earlier than 1841 will only be found from the specific county or even town clerk where the event took place. This can be hard to search if you don't know the exact location. Given the age of the county, there are actually quite a number of records older than 1841 so it is likely worth the effort. The county clerks in Barnstable should either have the records, or direct you to the proper town clerk.
Barnstable County Birth Records
Unlike many other states, Massachusetts does not have any relationship limitations on getting copies of birth certificates. So you can order any Barnstable County birth record that you wish. Recent records are easy to acquire but if you are looking at pre-1841 material, you can also use several genealogy sites online to do further research as these public records are available as indexes. Otherwise, you have to contact the clerk's offices as mentioned above. A mailed in application will cost $28 but the fee is only $18 if you arrive in person.
Barnstable County Death Records
Barnstable County death records are also issued to anyone who requests them, regardless of relationship. The cost for a certified copy is the same as with birth records.
Barnstable County Marriage Records
Just like the other types of records, Barnstable County marriage records are freely accessible regardless of age or relationship. Copies can be ordered in the same way, and the fees are also the same.
Barnstable County Criminal Records
Criminal records for any county are accessed through the Department of Criminal Justice Information Services (DCJIS). They will issue copies of your criminal history, and certain records for other people depending on then nature of the crime and the sentence. Their website has all the details. It will cost $30 to get a copy of a Barnstable County criminal record.