Suspects, captured before stabbing on MBTA camera.

Three Dorchester teens were scheduled for arraignment Wednesday on charges they beat and stabbed a teen on Tremont Street near Boston Common on Friday afternoon, the Suffolk County District Attorney's office reports.

Johnnie Bonnie, 18, Jermaine Gillespie, 17, and a third teen, not identified because of his age, were arrested last night by the Boston Police Youth Violence Strike Force. MBTA Police and the DA's office joined with Boston Police in the search for the three.

All three were ordered held in lieu of $200,000 bail at their arraignments on Wednesday, the DA's office reports.

The victim, brought to Boston Medical Center in critical condition, is expected to survive, the DA's offce says.

According to the DA's office, the three were tracked to a Dacia Street apartment. When they heard police at the front door, they attempted to run out the back - where they were promptly arrested. The DA's office adds all three were wearing the same blood-spattered clothing witnesses saw them in following the beating and stabbing.