WASHINGTON — The Justice Department said Sunday that it was restarting its investigation into the 2012 shooting death of Trayvon Martin to consider possible separate hate crime charges against George Zimmerman.

Mr. Zimmerman, the neighborhood watch volunteer who shot Mr. Martin, was acquitted of all charges by a jury late Saturday.

The federal inquiry, which was started shortly after the shooting last year but had been delayed while the state criminal trial in Florida was under way, was being restarted after civil rights leaders called on the Justice Department to re-examine the case. The leaders said Sunday that they remained convinced that the shooting had a racial element. Mr. Martin, 17, was black.

“There is a pattern of George Zimmerman making dozens of calls to 911 over several years, frequently about young men of color,” Benjamin T. Jealous, the president of the N.A.A.C.P., said in an interview on Sunday. Mr. Zimmerman and his family have defended the shooting as an act of self-defense.