With his last breath, Aaron Hernandez may have snatched from Odin Lloyd’s family whatever modicum of justice they received from his conviction.

An obscure legal doctrine in Massachusetts allows courts to vacate convictions for those who die before their appeals are exhausted. First-degree murder convictions prompt an automatic appeal and Hernandez’s bid had yet to be heard by the state’s highest court. That returns the case to its original status, as if Hernandez had never been tried or convicted.

The former New England Patriots star was found hanged in his cell last Wednesday at the Souza-Baranowski Correctional Center in Shirley. Authorities say it’s a probable suicide, but an investigation is ongoing.

How bitter this must be for Ursula Ward whose only son was shot to death by Hernandez, his body left in a North Attleboro industrial park by a man he considered a friend. In life, Hernandez was a convicted murderer sentenced to life without the possibility of parole; in death, he’ll likely become an innocent man.

John M. Thompson, Hernandez’s appellate attorney, told The Globe Wednesday that when a death certificate is available he would file a motion for the 2015 conviction to be voided. However his short, misspent life is remembered, Hernandez’s official record will show that he killed no one.

Massachusetts is one of several states with a centuries-old legal principle called “abatement ab initio.’’ Translated, “ab initio’’ means “from the beginning,’’ and it won’t be the first time it has been evoked here. John C. Salvi III committed suicide less than a year into his sentence for killing two women in two Brookline reproductive health care clinics in 1994. A fellow inmate (in the same prison where Hernandez died) murdered John Geoghan in 2003, a year after the defrocked pedophile priest was sent to jail. Both men had their convictions tossed out.

Of course, this doctrine only gets any attention when it benefits a high-profile convict whose guilt, in the public’s mind, is beyond question. Yet it is designed to protect all defendants. If someone dies after conviction, but their trial was marked by possible legal irregularities or prosecutorial misconduct, it shields those who may have been wrongly convicted. It upholds the appeals phase as an equally important part of the legal process; when that phase is unresolved, even a deceased defendant’s rights are taken into account.

Perhaps this is why a move by the state Legislature to prevent voided convictions died in the House 20 years ago.

For Lloyd’s family, Hernandez’s conviction must have been an unexpected deliverance. With no murder weapon or witnesses, prosecutors built their case on circumstantial evidence. They also faced a famous defendant, and the confounding ways that celebrity can charm star-struck jurors. For those who have suffered, a conviction brings some solace. It does not repair all, but it’s vital for someone to be held publicly responsible. Accountability can allow a family to heal and move toward lives of, albeit altered, normalcy.

Through her attorney, Ward says she will go forward with a wrongful death lawsuit against Hernandez. Though Hernandez was recently acquitted of the 2012 murders of Daniel de Abreu and Safiro Furtado, their families are also pursuing a civil case. But that has become more complicated. If Hernandez’s conviction is negated, evidence from his trial can’t be used in court and there can be no mention of that conviction since, technically, it will no longer exist.

During Hernandez’s trial, Ward said in court that she forgave “the people that had a hand in my son’s murder, either before or after.’’ Hernandez’s death ended his life sentence. It may be too much to ask a grieving mother to forgive the state for a necessary but archaic rule that could undo a jury’s guilty verdict.

For Ward and her family, justice served may soon become justice abruptly denied.

Renée Graham can be reached at renee.graham@globe.com. Follow her on Twitter @reneeygraham