Read the following sentence.
ex convict was released after pleading no contest to all charges.
edit the above sentence and include the correctluse of hyphens.
ex-convict was released after pleading no-contest to all charges.
exconvict was released after pleading no-contest to all charges.
ex-convict was released after pleading no contest to all charges.
ex convict was released after pleading no contest to all charges.

Ex-convict was released after pleading no contest to all charges is the correct use of hyphens.

Ex-convict was released after pleading no contest to all charges.

Explanation:

A hyphen "-" is an accentuation mark that is utilized to join words or parts of words. For the most part, hyphenate at least two words when they precede a thing they alter and go about as a solitary thought. This is known as a compound modifier. At the point when a compound descriptive word follows a thing, a hyphen is normally redundant. In any case, some settled compound modifiers are constantly hyphenated.  

For example:

Ex convict was released after pleading no contest to all charges, when other punctuation would be awkward. For instance, Ex convict can replace to Ex-convict at the sentence.