WHAT IS PRESERVING THE ISSUE
In a criminal case a defendant has the right to an appeal. This means the defendant has a right to have a higher court review his/her case for error. There are two types of error the appellate court will look at: 1) fundamental/plain error; and 2) preserved error. Fundamental/plain error is the hardest error to prove on appeal. It means that the issue was not preserved for appeal (which will talk about later), but the error calls into question the very foundation on which the case was decided. Preserved error is error that was raised at the trial, the trial court erred in its ruling, and the attorney claiming error took sufficient steps required by the appellate courts to review the error.
WHAT ARE SUFFICIENT STEPS TO PRESERVE AN ISSUE
Sufficient steps necessary to preserve an issue for appeal will vary from issue to issue. For example if the government wants to introduce inadmissible evidence, defense counsel must object to the evidence coming in, and state the grounds for the objection. If the defense counsel wants to introduce evidence, and court does not allow the evidence to come in at trial, then the attorney must ask the court to proffer the evidence. A proffer is where the defense requests to put the evidence he wanted to introduce at trial on the record (the record is what happened at trial. It will be what the appellate court reviews on appeal) for the appellate court to review.
WHAT HAPPENS IF THE COURT COMMITTED ERROR
Just because a court commits errors in their rulings it does no mean that the defendant is entitled to relief. There must be prejudice that resulted from the courts error. For example if the court erroneously excludes evidence on the wrong grounds, but it could have been excluded on other grounds then the error is harmless, because the evidence would not come in.
Preserving the issue for appeal is very important to ensure that a defendant receives a fair trial. However most the errors that occur at trial are not properly preserved for appeal, and the appellate counsel will have to argue fundamental/plain error to the appellate court. Unfortunately courts will rarely say that error raised to the level of fundamental/plain error, and sustain the conviction.