Transit Police report arresting a Jamaica Plain man on charges he took out a knife on the Orange Line and threatened another rider with it around 3:40 p.m. on Saturday near Tufts Medical Center.

Demond Perry, 44, was arrested yesterday at the Chinatown station on a charge of assault with a dangerous weapon, police say.

Innocent, etc.

Boston Police are trying to figure out where a man who wound up on an Orange Line platform at Downtown Crossing bleeding from a fresh stab wound around 8:20 p.m. was actually stabbed. Read more.

Transit Police report they are looking for this grinning man for an incident at the State Street T stop around 11:10 p.m. on Sunday, in which he allegedly attacked and kicked a person, then forced the person to a nearby ATM to withdraw money.

If he looks familiar, contact detectives at 617-222-1050 or send an anonymous text tip to 873873.

The MBTA reports Orange Line delays of 15 minutes due to an inbound train with a "mechanical issue" at North Station.

The MBTA is reporting Orange Line delays of 15 minutes due to switch problems at Forest Hills, which mean there is only one track at the station right now.

The MBTA, which had hoped to get the two new trains back in service by today, now says it and the manufacturer need more time - just how much they didn't say - to fix whatever's wrong with the "bolsters," part of the mechanism that keeps the wheels attached to the rest of their cars. Read more.

The MBTA reports residual inbound delays of ten minutes on the Orange Line stemming from problems getting a door on one train to work at Assembly.

Trains on both the Orange and Red Lines took a look at the thermometer earlier this morning and decided not to get out of bed, causing delays for people who had reasons to be places. Both lines are now back to normal, the T reports.

The MBTA reports Orange Line delays of up to ten minutes due to a train with one of those embarrassing mechanical problems near Wellington.