Investigators are still trying to establish a motive for the shooting suspect, who they have identified as a while adult male who was armed with a long gun.
An official close to the investigation said facial technology has been used to identify the suspect, after his damaged fingerprints made thumb print identification difficult.
Five people have been confirmed dead in the shooting in the US state of Maryland, and at least three people have been "gravely injured" as investigators question the suspect.
"There's five fatalities that we know of. There's several other persons that are gravely injured," deputy police chief of Anne Arundel county Bill Krampf told reporters.
Earlier, an explosive device was been found at the site.
