A controversial attorney won preliminary approval Thursday for a top Justice Department post, despite heated opposition over his ties to the case of a convicted cop killer.

The Senate Judiciary Committee, in a 10-8 vote along party lines, approved Debo Adegbile to lead the Civil Rights Division. The nomination now goes to the full Senate for final approval.

The nominee has faced criticism for his role, as acting director of the NAACP Legal Defense and Educational Fund, in getting Mumia Abu-Jamal's death sentence overturned.

Abu-Jamal was convicted in the 1981 killing of Philadelphia police officer Daniel Faulkner.

Supporters, including Chairman Patrick Leahy, D-Vt., said Adegbile has been unfairly criticized for his involvement in that case. But Republican opponents, and the widow of the fallen officer, voiced serious concerns about his judgment.

Sen. Chuck Grassley, R-Iowa, said Adegbile took up a "cause" based on the notion that the country's "most notorious cop-killer ... was a victim."

The officer's widow, Maureen Faulkner, wanted to testify on Thursday but Leahy did not allow it.

"I am physically, emotionally and mentally distressed that I'm not able to be in that room," Faulkner told FoxNews.com by phone on Wednesday. "This is personal to me."

A Leahy spokeswoman told FoxNews.com that a hearing to consider Adegbile's nomination was already held on Jan. 8, and lawmakers were allowed to ask questions on his background then. She reiterated that "it's not the practice" of the committee to have outside witnesses.

Those who know Adegbile personally, however, said he's the best man for the job. One such supporter is Terrance Daniels, a retired detective from the New York City Police Department. In a letter to the Senate committee, Daniels, who has known Adegbile as a classmate, co-worker and friend throughout three decades, said Obama's pick has "always been known" for having the highest integrity and character.

"He has always displayed a work ethic that would be hard to duplicate," Daniels wrote. "His knowledge of individual's legal rights will be perfectly used in the position he has been nominated for. He will protect everyone's civil rights with an enthusiasm and knowledge that will be second to none."