UPDATE: Police said Wednesday the suspect was plotting an ISIS-style attack involving the beheadings of police officers.

A second man has also been arrested in a nearby town. 

Here is the latest details.

A man who was being watched by the Joint Terrorism Task Force was shot dead by authorities this morning outside a CVS in Boston. 

Molly Line reported the latest on "Happening Now," saying that FBI and Boston police investigators approached the man to ask him some questions.

He then pulled out a black military-style knife and lunged at investigators. 

Police Commissioner William B. Evans said the officers gave the suspect several commands to put down the weapon before they opened fire. 

The suspect was transported to a local trauma hospital, but did not survive his wounds. 

The crime scene is located in Roslindale, described as a quiet, residential area of the city. 

Line said it's still unclear why the suspect was under surveillance by the Joint Terrorism Task Force. 

She said all that is known about the suspect so far is that it was a male in his 20s.

UPDATE, 3:45p ET: Multiple outlets are reporting that the suspect may have been inspired by ISIS. 

The photo below shows the knife at the scene. 

UPDATE, 7:52p ET: Molly Line reported the latest on "On The Record," saying that authorities have identified the deceased man as 26-year-old Usaama Rahim.

Line said that according to federal investigators, Rahim was very active on social media and that he was possibly radicalized by looking at ISIS propaganda online. 

Watch the full report above. Stay tuned to Fox News for more on this developing story. 

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