An M.I.T. dean was charged with disturbing the peace during Monday night's Radcliffe riot when he appeared in East Cambridge District Court yesterday to plead leniency for 17 Tech students facing the same charge.

Cambridge patrolman John Grainger accused Frederick G. Fassett, Jr., associate dean of students, of dropping water bombs on a police car. Another patrolman said he thought Fassett "incited" 200 students to raid Radcliffe in quest of "dainty souvenirs."

Only one of the 17 M.I.T. students pleaded "not guilty" to the charge of disturbing the peace. On the other hand, both Harvard students arrested in the disturbances, Addison Closson, Jr. '55 and Kenneth Huggins '55, were found not guilty. They were returning from dates shortly after the Tech students had been dispersed when police arrested them.

Dean Fassett had asked the court to continue the case until Tuesday, May 13, and the M.I.T. contingent was about to leave the courtroom when the patrolmen registered their complaints against him. Fassett requested a continuation in order to give Tech authorities time to investigate the affair.

Last night, M.I.T. President James R. Killian defended the Dean. He said that he has known the 50-year-old Fassett since he joined the college 20 years ago and that he is "a man of impeccable character and a highly respected college and student advisor."

"Fassett did not leave the campus last night and while on the campus did every thing to dissuade the students from leaving," Killian said. "The only explanation of the charge against Fassett is a mistake in identity."

Meanwhile, City Councilman Edward A. Sullivan said he would introduce an order asking for a conference of local college representatives to determine a method of restoring peace and quiet to Cambridge evenings