The Harvard Police have mobilized a special task force recently to combat the unusually high number of crimes in the McKinlock area of Leverett House, Saul Chafin, chief of University police, said yesterday.

Police reported seven thefts and one mugging in this area during the last two months, Chafin said. He added that "more uniformed and plainclothes police guard the area under the new program."

Kenneth R. Andrews, master of Leverett House, said yesterday students frequently unlock entry doors. In one week, entry doors had to be relocked 40 times during the 5 p.m. to 1 a.m. period, Barney Tierney, Leverett House superintendent, said yesterday.

Police found no signs of forced entry in the recent thefts, Chafin said, adding that some of the students had left their suite doors unlocked. The stolen goods were mostly stereo equipment, typewriters and cameras, he added.

"It doesn't take long to enter a room and make the theft," Chafin said. Deterrence is weak if students leave doors unlocked and never challenge or report suspicious persons, he added.

In addition to the increased patrolling in the area, police have instructed the superintendent to keep the House's gate facing Memorial Drive locked, Chafin said. While there is no guard in the McKinlock entrance, there should be three locked doors between the courtyard and Mill Street, Andrews said.

Last Tuesday, in the most recent crime in McKinlock area, about 11 p.m. two males robbed a Leverett House sophomore at knifepoint, the victim, who wished to remain unidentified, said yesterday. The muggers took the $10 out of his wallet and handed it back to him, the victim said.

"As far as muggers go, they were as friendly as they could be," the victim said, adding that the muggers were apologetic.

Police made no arrests and there are no substantial leads, Chafin said yesterday.