At this point in the story, everyone is familiar with the big yellow bird that appears in Perry's dreams and even sometimes in visions. This bird is considered by Perry to be a liberator, as Perry "sees" it take away his burdens. Because of this trait of the bird, I argue that Perry was not influenced by Dick to murder the Clutters, nor did he commit the act in resentment to the Clutters themselves.
The big bird was first mentionned when Perry described his childhood with the nuns, where the bird "slaughtered them as they pladed for mercy" (93). In that situation, Perry was freed from the constant pain and suffering that the nuns put him through. From there, the bird appeared in almost a pattern-like manner. It seemed to save Perry from his superiors, as many of them treated him badly. From all of this, it can safely be established that the big bird appears to Perry only when he is in need. Therefore, if Dick was manipulating him to an unbearable degree, would Perry not have desires of seeking revenge on Dick now that they were both in prison? No, Perry did not have any such feelings because Dick, being "such a coward," (255) did not advise him to murder the Clutters in the spur of the moment.
Perry also did not kill the Clutters for any particular reason. Many have argued that he wishes nothing but malice towards those who live good lives, the types of lives that Perry never had the chance to live. This, some say, caused him to kill the Clutters, because they were a well-off family who were very happy with their lives. However, this is completely false. For one thing, it is already established that the big bird is a symbol for a destroyer of all that Perry hates. He has seen this bird in dreams regarding "older children, his father, a faithless girl, a sergeant..." (93) Basically, all of Perry's dislikes and burdens are marked by the appearance of the bird. This caused me to wonder: If he truly resented the Clutters for their wealth/happiness/etc, why did he not even mention the bird when thinking of the Clutters? This is because he never hated the Clutters to begin with. Furthermore, Perry said to Don Cullivan "I was willing to take that gamble. And it wasn't because of anything the Clutters did. They never hurt me" (290). There is no clearer piece of evidence to suggest that Perry was ambivalent to the Clutters.
Regardless of Perry's true reason for his crime, whether it be insanity or anything else, he was certainly not manipulated by Dick to commit the act, and he did not kill the Clutters out of resentment or malice.