CAMBRIDGE — A suspected subway pervert is on the loose after MBTA Transit Police released a photo of a man accused of committing a lewd act aboard a Red Line train, the latest disturbing incident in a transit system riders say feels increasingly lawless.

In a public alert, Transit Police said the incident occurred on December 29 around 7 p.m. on a Red Line train near Harvard Square. However, the alert was issued earlier in the day, and police appear to have misstated the date. As a result, the exact timeline of the incident is unclear, though authorities say the alleged act occurred recently.

Investigators allege the man intentionally sat across from a woman and performed a lewd act while staring at her, before police were able to identify him.

Help us ID this deviant:12/29 7PM #MBTA Red Line train outside Harvard Sq. Male intentionally sat across from a female passenger and committed a lewd act while staring at her. Recognize him? Pls call our CIU at 617-222-1050 w/any info you have. You can remain anonymous. TY pic.twitter.com/T1MPvQ7yJl

— MBTA Transit Police (@MBTATransitPD) December 29, 2025

Transit Police released a photo of the suspect and are urging anyone who recognizes him to contact the MBTA Transit Police Criminal Investigations Unit at 617-222-1050. Tips may be submitted anonymously.

The allegation adds to a growing list of MBTA crime alerts that have turned suspect photos into a routine feature for riders — from random assaults and threats to track pushings and now alleged sexual misconduct on crowded trains.

No arrest has been announced. The investigation remains active.