The Karen Read murder trial will be underway in Norfolk Superior Court in Dedham at 9 a.m. with a key witness expected to take the stand.

While Judge Beverly Cannone and attorneys on Wednesday described the upcoming testimony as coming from “that one witness” for some reason, prosecutor Adam Lally had indicated in a prior day that Brian Higgins was coming up. All the other witnesses he said were coming up have already taken the stand.

Higgins is a Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) agent with keycard access to an office in the Canton Police Department, officers there have testified earlier in the Read trial.

He is also on the short list that defense attorney David Yannetti presented during a pre-trial hearing as a possible alternative killer in the defense’s third-party culpability theory. They say he, or in conjunction with the other two, beat O’Keefe to death and laid his body on the front lawn to frame their client.

This is a developing story.