By Eric Levenson

CNN

FALL RIVER, Massachusetts (CNN) -- Aaron Hernandez died as a convicted murderer, but in the eyes of the law, his conviction has been erased.

A Massachusetts judge has ruled to vacate Hernandez's murder conviction after the former NFL star's suicide.

Hernandez was serving a life sentence for the June 2013 murder of Odin Lloyd. Hernandez hanged himself in his prison cell on April 19, just days after he was acquitted of double-murder charges in a separate case.

Massachusetts courts have generally recognized a legal rule called "abatement ab initio," or abatement, in which convictions are thrown out if a defendant dies before their appeal is heard.

The idea of abatement is to ensure the right to appeal for defendants, Suffolk University law professor Rosanna Cavallaro told CNN.

Hernandez's defense attorneys asked the court to follow that procedure and toss out his April 2015 murder conviction for killing Lloyd.

Hernandez attorney John Thompson said the manner of death should not matter -- when a person dies while his conviction is under direct appeal, the conviction should be vacated.

But prosecutors from the Bristol County District Attorney's office opposed that motion. They argued that abating Hernandez's conviction would "reward the defendant's conscious, deliberate and voluntary act" of killing himself, and that the abatement rule has no solid historical or legal basis.

"A defendant, who can cut off his own criminal appeal by suicide and stall civil litigation by a stay of proceedings ... has the reins of the entire justice system in his own hands," prosecutors wrote.

In court filings last week, prosecutors produced two pieces of evidence they said bolster their argument.

First, one fellow inmate told authorities that Hernandez had mentioned he heard a "rumor" about the abatement rule, according to the court documents.

Second, Hernandez's suicide note for his fiancée said "YOU'RE RICH," underlined twice. The issue is relevant because Lloyd's mother, Ursula Ward, had sued Hernandez's estate in civil court in a wrongful death lawsuit. And civil lawsuits often rely on a criminal conviction as their basis of facts.

In Massachusetts, abatement has generally been recognized even in high-profile cases of suicide.

John Salvi was convicted of murder in 1996 for opening fire at a Planned Parenthood in Brookline, but his conviction was vacated when he committed suicide in prison before his appeal was heard.

And the death of John J. Geoghan, a priest at the center of the Catholic Church's sexual abuse scandal, also led to the abatement of his conviction.

CNN's Holly Yan contributed to this report.