Swirling in controversy, the murder case against Karen Read gets underway Tuesday in Norfolk Superior Court in Dedham. The case has generated publicity, outside attention and even scrutiny from federal justice officials.

Read, 44, is accused of killing her boyfriend, Boston Police officer John O'Keefe, outside a home in Canton two years ago. Prosecutors in Norfolk County say Read ran over O’Keefe with her SUV during a blinding January snowstorm and then left him to die in the cold.

Charged with second-degree murder, vehicular manslaughter while under the influence of alcohol and leaving the scene of an accident, Read has pleaded not guilty. Her defense attorneys claim she is the victim of a coverup involving local and state police. They allege that 46-year-old O’Keefe wasn’t hit by Read’s car but instead was severely beaten inside the Canton home owned by a then-Boston police sergeant, bitten by the family’s German shepherd, and his body left outside.

Adding fuel to Read’s defense is a yearlong federal investigation into the state’s prosecution of Read. Legal observers say that convening a federal grand jury to investigate an active murder case casts uncertainty over the trial.

 “For this to be out in the open, that there is a federal investigation right as the jury selection is starting, as the trial is starting, is really unfortunate,” said Angelo Petrigh, a professor at Boston University School of Law who specializes in criminal defense.

Petrigh added, “It also just leads me to the worry that whatever happens is not going to be viewed as legitimate or proper and might be the potential for just having to retry this anyway based on what comes out of the federal investigation.”

New York and some other states have enacted statutes that require the attorney general’s office — instead of local police and prosecutors — to handle serious cases in which a law enforcement official is a victim or accused of misconduct, said Petrigh.

The fact that O’Keefe and the Canton homeowner were both police officers has also helped feed conspiracy theories along with demonstrations outside the Dedham courthouse.

Blogger, Aidan Timothy Kearney, known as “Turtleboy,” published a stream of posts alleging a police coverup but now faces charges of intimidating several witnesses in the Read case in addition to a conspiracy charge.

Chris Dearborn, a professor at Suffolk Law School who runs a criminal defense clinic, said Read’s defense lawyers should distance themselves from Kearney.

All the social media publicity and the federal investigation, Dearborn said, will mean a very long jury selection process.

 I wouldn't want a potential juror to think that Karen Read or her lawyers orchestrated that whole campaign with the (Turtleboy) blogger,” said Dearborn.

“Even in the last five years, the role of the media and social media and sensationalizing criminal cases everywhere and in Massachusetts has grown exponentially,” said Dearborn.

He added that the sensationalism in this case has gone “to another level.”