Updated

A top presidential adviser said President Obama's decision to comment on the shooting death of an African-American teenager in Florida was motivated by parental instinct more than the incident's emergence as a racial issue.

Senior White House adviser David Plouffe said Obama reacted instinctively as a parent last week in saying that Americans needed "some soul searching" in the wake of the slaying of 17-year-old Trayvon Martin by a neighborhood watch volunteer. The gunman was not charged, prompting probes by the Justice Department and local authorities.

Obama said he supported the investigations, noting: "If I had son, he'd look like Trayvon."

Speaking on "Fox News Sunday," Plouffe said Obama "was speaking powerfully about this as a parent." Plouffe added that "no matter gender or race, this is a tragedy."