During the Television Critics Association press tour this week, ABC News President Ben Sherwood said reporter Brian Ross' incorrect speculation about the Aurora movie theater shooter "was an unfortunate mistake" that "did not live up to the standards and practices of ABC News."

He also said the network was taking steps to avoid future mistakes of this nature.

ABC News already issued a public apology after investigative reporter Brian Ross went on "Good Morning America" and incorrectly said movie theater shooter James Holmes     may have been a member of a local tea party chapter.

The Los Angeles Times quoted Sherwood's remarks at the Television Critics event: "We put something on the air that we did not know to be true and the part that we needed to be true was not germane to the story we were covering," he said.

Sherwood added "that the network was taking steps to make sure it does not happen again, although he declined to say specifically what those steps were."

He also told the audience Ross had contacted the wronged Mr. Holmes to apologize.

"This was an unfortunate mistake," Politico also quotes Sherwood as saying. "We recognized it immediately, we owned it immediately, we corrected it immediately. We know that particular moment did not live up to the standards and practices of ABC News. I take responsibility for it. The buck stops with me and the news division knows how displeased I am with that."

Good Morning America host George Stephanopoulos was on the air with Ross when he made the mistake. At the Television Critics event, he joined in by satellite to say, "This was a breaking news situation and people are going to make mistakes."

Though Sherwood acknowledged Ross' error, he defended another controversial piece of ABC News reporting. The network had reported that Holmes' mother said "you have the right person" when it contacted her to ask if her son was the shooter. She has since said she was referring to herself to let the reporter know she was Holmes' mother.

Sherwood said the network "stands by" its reported version of the conversation.

He however didn't say anything about another recent dispute regarding his network's reporting. After ABC News reported that Holmes was repeatedly spitting at his prison guards, yesterday an ABC affiliate in Colorado published a report that said the spitting claim was "simply false."