Did the prosecution's suppression or withholding of state's key witness' prior violent criminal history that was favorable to accused for impeachment purposes, violate defendant's due process to the 14th Amendment under Brady?

Questions presented continued... No. 3 o. 3 Petitioner contends that his trial counsel's prior representation of this case!s state's key witness against accused, violates his 6th Amemdment right to effective assistance of counsel and shows a fundamental unfairness, when counsel refused to impeach state's witness (Galvan) on the stand forhis extensive violent criminal history to the jury. also to his affiliation to (T.S.),"prison gang". Counsel failed to notify his client to the prior representation until defendant requested the criminal background trvestigation of state's witness prior to trial for impeachment purposes. Petitioner knew (Galvan) as a member of a violent gang called Texas Syndicate , founded within Texas prison system in the 1970's but now on the outside, the gang called Austin,Texas their home base city. Trial counsel for petitioner failed to reveal his prior representation to his client, (defendant) until he asked for his criminal history and counselvréfused to investigate and reveal all of the prior arrest and convictions within Galvan's history. see; attached Galvan's criminal arrest sheet. Counsel later told client that even though state's witness had some assaults, they were older than "Ten years", and indicated that he wasn't going to jeopardize he and Galvan's relationship by impeaching him on the stand for me on such an old record... Petitioner shows within attached criminal history that was withheld from him at the pre-trial, that a few of the arrest were less thaw 5 years old, at the time of request during 2008-09 pre-trial. see; arrest sheet attached Did the State prosecution. withhold Brady material favorable to defense, to key witness violent criminal history for impeachment purposes??? : Did trial counsel violate his client's 6th Amendment right to effective assistance of counsel when counsel fefused to investigate state's witness criminal history for impeachment purposes to the jury??? . Did trial counsel create a conflict of interest that denied his client right to counsel and a fair trial??? see; goundsthree , Cert