Why Does the U.S. Have an Exclusionary Rule?

In my view, the fact that crim­i­nal pro­ce­dure rules are judge-​​made led fairly directly to the exclu­sion­ary rule. Put sim­ply, the exclu­sion­ary rem­edy is the one rem­edy that judges can com­pletely con­trol. There are a vari­ety of ways to enforce rules of crim­i­nal inves­ti­ga­tions, such as law­suits, crim­i­nal pros­e­cu­tions, and inter­nal dis­ci­pline. But all of these alter­na­tives tend to require the coöper­a­tion of other branches. The rules gov­ern­ing civil law­suits are largely under the legislature’s con­trol. Legislatures can reg­u­late juris­dic­tion, cre­ate pro­ce­dural hur­dles, limit dam­ages, and the like. And crim­i­nal pros­e­cu­tions and inter­nal dis­ci­pline require the coöper­a­tion of the exec­u­tive branch. Someone in the exec­u­tive branch needs to see the vio­la­tion as a major prob­lem and needs to take action to enforce the law.

Interesting arti­cle by Orin Kerr. See:
http://​volokh​.com/​p​o​s​t​s​/​1​2​1​6​4​9​8​4​6​7​.​s​h​tml