Alexander Pring-Wilson, the former Harvard graduate student convicted of manslaughter last year, will be freed today, awaiting a new trial, if he posts $400,000 bail.

Last Friday, the judge in Pring-Wilson’s case vacated his six-to-eight year sentence and gave him a retrial.

Guided by a recent Mass. Supreme Judicial Court (SJC) decision, Middlesex Superior Court Judge Regina L. Quinlan decided that during the trial she had improperly disqualified evidence about the violent pasts of Pring-Wilson’s victim and the victim’s cousin.

Pring-Wilson, who was until 2003 a student at the Davis Center for Russian and Eurasian Studies, has been in prison since October 2004, when a Middlesex County jury found him guilty of voluntary manslaughter in connection with the 2003 stabbing death of Cambridge teen Michael D. Colono.

Pring-Wilson, now 27, encountered the 18-year-old Colono and Michael D. Rodriguez, Colono’s cousin, outside a Cambridge pizza parlor on April 12, 2003, as he was walking home after a night of drinking. A fight erupted between Pring-Wilson and Colono and his cousin­, with each of the two sides later claiming the other was at fault. Pring-Wilson fatally stabbed Colono during the altercation.

During the original trial, jurors learned that both Colono and Rodriguez had criminal histories, but they were not told many specifics. The new trial will include more of these details.

Colono had been convicted of possessing cocaine during an incident at another Cambridge pizza parlor in September 2001. Colono kicked in the store’s glass door.

Rodriguez has had several convictions for assault and battery. He was also charged in 2001 for unlawful possession of a firearm, according to court documents.

Pring-Wilson, who has no prior criminal record, is the son of two Colorado lawyers. His family has been able to meet $400,000 bail before.

At a hearing at the Middlesex County Courthouse Monday, the prosecution and defense sparred over the conditions of Pring-Wilson’s bail.

“Having had a taste of incarceration, there is a tremendous incentive for the defendant to avoid jurisdiction,” said Assistant District Attorney Adrienne C. Lynch, who led the prosecution during the original trial.

Lynch said that Pring-Wilson should be considered a flight risk for several reasons, including his “being a world traveler, [his] speaking several languages, and his considerable personal assets.”

But Charles W. Rankin, Pring-Wilson’s lawyer, noted that Pring-Wilson had not once violated the terms of his release during the 17 months he was free for the original trial. He also has an unblemished disciplinary record at the Bay State Correctional Center in Norfolk, Mass., according to Rankin.

“My suggestion is that he be permitted to go and live with his family in Colorado,” Rankin said. He also requested Pring-Wilson be set free without having to post bail.

Quinlan sided with the prosecution, which had asked for the same restrictions to be imposed on Pring-Wilson as in his 2004 trial.