Mayor Higgins, who was last seen eating a giant donut, is our prime suspect. We need to find the specific donut shop that sells these rare rainbow sprinkles. The Golden Crumb Bakery, which is located on Main Street, was robbed at midnight.

When to use commas:

• When a person or place is uniquely identified by their proper name (Mayor Higgins, The Golden Crumb Bakery), any descriptive clause that follows is just extra information. This is a non-defining clause. It needs commas, and you must use "who" for people or "which" for things (never "that").

• When the noun is general and needs identification ("the specific donut shop"), the clause is defining. It provides essential information, so we use no commas and can use "that".