A Dartmouth man facing charges of extortion and making threats following an 8-hour standoff with police, appeared Thursday in New Bedford District Court.

A "not guilty" plea was entered by an attorney for Kevin Pacheco. He was ordered held without bail for a dangerousness hearing on Monday.

Pacheco is accused of making threats to the Roger Williams University Law School this week in a 35-page email. He was a former student there.

Prosecutor Patrick Driscoll said in court, Pacheco has a history of mental illness.

A defense attorney argued that Pacheco had not threatened any specific individual.

After the standoff, police searched Pacheco's home, and found five weapons, along with ammunition and bottles of various medications.