Some time late in the day or early evening of Jan 25 a bunch of guys met up in Mattapan where some of them lived; they were hanging out together and drove here and there in a van owned by one of them (or his father). There was no evidence presented that they were part of a gang, nor that they were on drugs or drinking. At some point that night they drove into Cambridge and were seen to be roaming around the Newtowne Court housing project where at least one witness said one of them had knocked her(his?) hat off.
They encountered Jesse McKie walking along with a friend and accosted him and tried to steal his jacket. A large knife (never found) was then used to stab Jesse a bunch of times. They then attacked Rigoberto Carrion who I believe was walking by and stabbed him, too. Both killings were extremely brutal with multiple stabbings in the chest/abdomen area.
The perps were all black and Jesse was white but there was no evidence introduced that even hinted that this was a racially motivated crime.
Much of this was seen by a resident in one of the apartments overlooking the spot and he called 911. I think while he was doing this he was not looking out the window and that was when the second homicide occurred. There were several other eye witnesses who saw part of these events. I don't recall that anyone saw the whole scene and part of what we the jury had to do was to piece together the events for which a clear scenario had not been presented by the prosecutor - perhaps the result of some of the many sidebars. It wasn't clear if there were two knives or whether the knife had been passed from one person to another and therefore whether more than one person did the stabbing.
Four people were accused of the two homicides and armed robbery, and the fifth (the van driver) was accused of being an accessory. Our trial included only 3 of the four individuals accused of homicide since the fourth was separated I believe because of contested admissibility of some piece of evidence.
In Massachusetts there is the concept of joint-venture which allows several people to be accused of a homicide if they were working together even if only one was the killer. The definition of working together is quite loose. First degree murder is punished by a life sentence without possibility of parole. There are three types of first degree murder - committed with extreme cruelty and atrocity, by deliberate premeditation, and a felony murder - that is if someone is killed even accidentally while committing a felony. Fortunately the judge after explaining all of this as well as what is meant by reasonable doubt and premeditation did give us a written version of her explanation that we could refer to during deliberations.