A person when dies his Facebook Account or Profile remains active. Since these accounts are active so other people can tag such profiles, post on their wall, etc just like other accounts.
Facebook has option to Memorialize an account (and will consider this account of a dead person). REMEMBERING will be added with such Profiles, such accounts will no longer be tagged, posted on their wall etc. Those who has authority (or given due authority) can post on their walls, change their dp, approve friends requests etc. Secondly, such accounts can be de-activated. If you want to memorialize or de-activate profile of a deceased person then keep watching.
Follow the given links to access Memorialization Request Form and Special Request for Deceased Person’s Account:
Memorialization Request Form: https://www.facebook.com/help/contact/234739086860192
Special Request for Deceased Person’s Account: https://www.facebook.com/help/contact/228813257197480