Whether petitioner received ineffective assistance of counsel when his counsel objected to a jury instruction on the untrustworthiness of co-defendant testimony without researching the issue?

QUESTION(S) PRESENTED The states key witnesses at a homicide trial were three charged co-defendants. Petitioner's defense rested upon undermining the credibility of the co-defendants’ accusations against the petitioner. The state offered a jury instruction on legal principals recognizing the untrustworthiness of the codefendants testimony. When petitioner's counsel--without research--objected to the entire instruction, didipdétittonier !réecteve ineffective assistance of counsel?