It is very easy to find four Amendments to the U.S. Constitution that concern criminal law.

Amendent 4: This protects against "unreasonable searches and seizures"; in other words, the police may not enter your home and search it unless they can show "probable cause" that it may contain items that are related to criminal activity.  

Amendment 5: a. You cannot be tried in court for a capital crime unless a Grand Jury has reviewed the case and feels there is sufficient evidence to prosecute.  b. You do not have to testify against yourself.  c. Private property cannot be taken for public use without "just compensation."  For example, if the government wants to knock down your house in order to build a highway, they must pay you a reasonable price for your house. 

Amendment 6: An accused person has the right to a "speedy" trial, by jury.  The accused must be informed of the charges against him.  The accused has the right to a lawyer to assist him or her. 

Amendment 8: The amount of bail that a prisoner needs to pay to be released from jail before trial may not be "excessive." "Cruel and unusual punishments" may not be used.

As for the fifth, I would choose the 18th Amendment, which made it a crime to sell  liquor, and the 21st Amendment, which repealed (overturned) the 18th.