What is ineffective assistance of counsel in a criminal case? Thanks to the Sixth Amendment and associated court rulings, criminal defendants are entitled to the assistance of counsel — and that counsel is to be effective. However, the standards for determining when counsel has been constitutionally ineffective are hard to meet.

First, the attorney must have failed to perform a legal duty toward the defendant. That could be, for example, the duty to perform a reasonable investigation of the case, to present favorable witnesses or to introduce any evidence pointing to the defendant’s innocence. Second, however, counsel is only considered ineffective if that failure to perform the legal duty can be shown to have impacted the outcome of the trial.

The Maryland Court of Special Appeals has just ruled that Adnan Syed received ineffective counsel eighteen years ago when he was convicted of killing his former girlfriend. The court ordered a new trial for Syed. However, the prosecution may choose to appeal the ruling.

You may know Syed from the first season of the podcast “Serial,” which chronicled his case. He was convicted in 2000 of murdering the young woman and burying her in a Baltimore park. He was convicted of murder, kidnapping, robbery and false imprisonment and sentenced to life in prison.

During his trial, however, his attorney did not bring an alibi witness into court. The witness, Asia McClain, apparently would have testified that she saw Syed at a library at the time the prosecution said the murder occurred. Syed’s trial attorney did not even contact McClain to investigate her claims.

The majority of the Court of Special Appeals found that Syed’s trial counsel had a legal duty to contact and evaluate the alibi witness. Moreover, it found that “there is a reasonable probability that McClain’s alibi testimony would have raised a reasonable doubt in the mind of at least one juror about Syed’s involvement.”

A single judge dissented, arguing that the trial attorney’s failure to contact McClain might have been a strategic decision. The attorney has, unfortunately, died since the trial.

The majority of the court vacated all of Syed’s convictions, finding that they were all predicated on the murder conviction. Since there was a reasonable probability that the murder conviction was tainted by ineffective assistance of counsel, Syed should be retried on all counts.

The State’s Attorney’s Office in Baltimore has 30 days to file an appeal. If it does not appeal, Syed could be retried. However, there are a number of difficulties in retrying a case so old, so the state might choose to offer Syed a plea bargain with a limited sentence — or even time served.