Whether a defendant can obtain exculpatory evidence withheld by prosecutors and challenge due process violations through habeas corpus when potentially innocent of the charged crime

1) How does a defendant obtain the evidence that proves his innocence when the prosecutor knowingly presents false evidence and refuses to turn over the exculpatory material documents so that the defendant can present them to the court and obtain the relief he deserves either in the trial district court, Oklahoma Court of Criminal Appeals, or getting relief through a Writ of Habeas Corpus and is it a violation of Due Process ? 2) Did the 10th Circuit Court of Appeals violate Due Process of Law and conduct Abuse of Discretion by not granting a Certificate of Appealability in order for Mr. Stevens to be able to appeal the denial of his Writ of Habeas Corpus to the Northern District of Oklahoma regarding exculpatory evidence that would potentially prove Mr. Stevens innocence to the specific crime he was charged with and not be barred by the AEDPA? 3) Are the specific text messages that Mr. Stevens is asking for not considered potentially exculpatory material evidence under Brady v. Maryland and a violation of the Due Process Clause to 14th Amendment to the U.S. Constitution and Okla. Const. Art. 2 § 7 due to being withheld by the prosecution ? 4) Did trial counsel conduct ineffective assistance of counsel under 6th Amendment to the U.S. Constitution for not acquiring the withheld text messages, and requesting that the prosecutor search for, obtain, and disclose the exculpatory material evidence, filing a preservation letter, and a Brady motion under Brady and Strickland v. Washington ? 5) Did Appellate Counsel, Mr. James H. Lockard, conduct ineffective assistance of counsel violating the 6th Amendment to the U.S. Constitution for not acquiring the excluded text messages that his client asked him to and present them to the court in his direct appeal?