DA: Young teen had help in attacking man he stabbed to death, used T stop to escape, left key behind

Ernest Watkins IV was arraigned today on charges he stabbed a man to death outside the Fields Corner T stop last week. Watkins is 14.

Watkins was among a group of four people spotted attacking Cherby LaJoie around 1:15 a.m. on Oct. 6, according to the Suffolk County District Attorney's office. MBTA surveillance footage shows the four entered the T stop - one jumping a gate after his CharlieCard wouldn't work - then fled out an emergency exit, the DA's office says.

LaJoie died from multiple stab wounds to the head and chest, the DA's office reports, adding that police recovered a key on a shoelace near LaJoie's body.

Prosecutors say that in addition to a trail of blood, investigators followed tips from witnesses and MBTA CharlieCard records, which led them to somebody who gave up the kid's name.

According to the DA's office, police went to his Dorchester home Saturday and, among other things, tried the key they recovered in his door. It worked.

Watkins was then put under arrest, his name to become available under a state law that mandates juveniles be tried in adult court in murder cases.

The DA's office says the investigation is ongoing and that additional people could face charges.

Innocent, etc.