KAREN NELSON MOORE, Circuit Judge. This case returns to us following the district court’s denial of Petitioner-Appellant Maurice A. Mason’s (“Mason”) petition for a writ of habeas corpus filed pursuant to 28 U.S.C. § 2254. In Mason v. Mitchell, 320 F.3d 604 (6th Cir. 2003) (“Mason I”), we remanded this case to the district court with instructions to hold an evidentiary hearing regarding Mason’s claim that he received ineffective assistance of counsel at the sentencing phase due to his counsel’s failure to conduct a reasonable investigation into his family background. After holding an evidentiary hearing on December 29 and 30, 2003, and January 6, 2004, the district court issued a Memorandum Opinion and Order denying Mason’s petition on October 31, 2005. Mason v. Mitchell, 396 F. Supp. 2d 837 (N.D. Ohio 2005) (“Mason II”) (Joint Appendix (“J.A.”) at 379-413). Although Mason’s counsel reviewed records provided by the state that contained some references to violence and drug use in the Mason family home during Mason’s childhood, Mason’s counsel failed to investigate Mason’s background and essentially conducted no interviews of any of Mason’s family members prior to settling upon a plan for the sentencing phase that was limited to appeals for mercy and claims of residual doubt. We hold that trial counsel provided ineffective assistance by failing to interview Mason’s family members and investigate the obvious red flags contained in state records suggesting that Mason’s childhood was pervaded by violence and exposure to drugs in the home from an early age. Accordingly, we REVERSE the judgment of the district court, GRANT Mason a conditional writ of habeas corpus that will result in the vacation of his death sentence unless the state of Ohio commences a new penalty-phase trial against him within 180 days from the date that the judgment in this matter becomes final, and REMAND the case for further proceedings consistent with this opinion.

McKEAGUE, Circuit Judge. This is an appeal from the denial of a petition for writ of habeas corpus. The district court issued a certificate of appealability on one issue, noting an apparent lack of uniformity among Sixth Circuit rulings. Finding that the issue certified for appeal has been definitively resolved by Sixth Circuit rulings rendered since the district court denied the habeas petition, we now affirm the denial of habeas relief.

The facts are not in dispute. Briefly, Parker was a member of large-scale powder and crack cocaine distribution and money laundering organization based in Dayton, Ohio. In 2004, he was charged with (1) conspiracy to distribute and to possess with the intent to distribute in excess of 150 kilograms of cocaine, and (2) conspiracy to launder money. Parker pleaded guilty to the two charges, knowing that the statutory maximum sentence was life imprisonment, the statutory mandatory minimum sentence was 10 years, and the applicable advisory guidelines range was 135 to 168 months. The district court sentenced Parker to the mandatory minimum sentence of 120 months.

A year after Parker was sentenced, the government filed a motion to reduce Parker’s sentence pursuant to Rule 35(b). Based on that motion, Parker was re-sentenced to 60 months in prison on both counts to run concurrently. Parker thereafter filed this timely appeal.

In this case, Parker contends that the district court’s decision to reduce his sentence to 60 months was unreasonable, the court having purportedly failed to take into consideration Parker’s peripheral role in the conspiracies, his age, and/or his employment history. Because 18 U.S.C. § 3742(a) governs this appeal, and because Parker has not raised any colorable claim that his appeal falls within the narrow jurisdictional parameters set out in section 3742(a), this court lacks jurisdiction to review the district court’s judgment reducing Parker’s sentence under Rule 35(b). Accordingly, we DISMISS Parker’s appeal of his reduced sentence.