The most senior police officer implicated in the slaying of Warsaw priest Jerzy Popieluszko said today that he had never authorized the use of force against the outspoken cleric and blamed the killing on the initiative of his subordinate.

Testimony by Col. Adam Pietruszka, a deputy department director in the Interior Ministry accused of aiding and abetting three junior officers in the killing, appeared to end speculation that the threat of a trial and stiff sentences might push the defendants to name higher ranking officials as instigators of the crime.

Grzegorz Piotrowski, the ex-captain charged with leading the assault, concluded on the stand earlier today that while he had been convinced that high-level backing existed for the plot, he now understands that the killing of the priest was never sanctioned by his superiors. He realized this, he said, when he saw Pietruszka's fury and shock at being told by Piotrowski two days after the killing that the priest was dead

Nevertheless, Piotrowski and two former lieutenants who with him kidnaped the priest, have testified that Pietruszka strongly suggested an operation against Popieluszko, even if such action might result in the frail cleric's death. They also have told of Pietruszka's involvement in a vain attempt by all four to cover up the crime.

Speaking with calm assurance, Pietruszka, a 46-year-old career policeman decorated with gold and silver merit crosses, denied instigating the Oct. 19 killing.

He confirmed that he did call a meeting in September that was attended by Piotrowski and a Warsaw militia official, Lt. Col. Leszek Wolski. At the meeting, they discussed the need to take action to restrain Popieluszko and another defiant Warsaw priest, the Rev. Stanislaw Malkowski. But Pietruszka said the measures brought up then involved writing protest letters to the Warsaw curia and conducting surveillance to collect compromising evidence against the clerics.

"I never proposed the use of force against the priest during the whole meeting," asserted Pietruszka.

Sometimes phrasing his remarks to Torun's provincial court in language thick with communist slogans, Pietruszka added: "Having been raised according to the principles of socialist humanism, we abide by the conviction that political enemies must be fought with political and social argument, not with force and fists."

The colonel described Piotrowski as a dynamic officer devoted to his job but showing "tendencies to be independent." Pietruszka claimed that an Oct. 13 trip to Gdansk by Pietruszka and two codefendants, Waldemar Chmielewski and Leszek Pekala, was to have been a scouting mission, but turned into an aborted attempt to abduct Popieluszko without the colonel's knowledge. When told later what had happened, Pietruszka said he scolded Piotrowski for insubordination.

He denied ever saying, as subordinates have alleged, that Popieluszko should be pushed from a train. Another remark attributed to him -- that the priest should be shocked to the verge of a heart attack -- may have come from him, he said. But if so, it was meant metaphorically and in no way was an order to attack Popieluszko.