Two Capitol Police officers were shot, two women were killed, and the gunman was fatally shot during a morning
The shooting was reported around 8 a.m.
The gunman reportedly began firing in the courthouse's lobby.
The gunman was shot to death in the courthouse lobby but authorities are investigating whether police shot him or he shot himself, Delaware State Police Sgt. Paul Shavack said in a mid-morning press conference.
One of the female victims was the shooter's daughter-in law*, according to NBC Philadelphia.
*Original reports said one of the female victims was the shooter's wife. However, a detailed story by Delaware Online that was published Tuesday said the woman was the shooter's daughter-in-law.
Wilmington Mayor Dennis Williams told The Associated Press the woman died as a result of the shooting. The couple were estranged, according to the AP.
State police confirmed to NBC Philadelphia the second woman died as well.
Both police officers are in non-life threatening condition, Shavack said.
"When I first heard about this, my first thought was that the only way someone could have gotten in there was to avoid the metal detectors, which is very hard to do, or go in firing," defense attorney Brian Chapman told NBC Philadelphia. "There are at least four or five rows of metal detectors when you go in, you put your belongings through, then you have to walk through the metal detectors. Then there are usually eight to 10 police with wands checking everyone and after that you still have to walk by a desk where capitol police sit."
Police stressed in this morning's press conference that the shooting happened in a public lobby and the gunman hadn't reached the courthouse's metal detectors or other security checkpoints.
Sandra Autman, a deputy clerk at the courthouse, told Delaware Online she heard "at least five shots" and heard a rumor the gunman walked into the lobby shooting.
Shavack confirmed multiple shots were fired but said they can't yet confirm what type of gun was used. Shavack said also are not yet identifying the gunman.
During a noon press conference, Shavack still declined to discuss motive or identify the shooter.
However, the shooting "stemmed from a domestic dispute," BloombergBusinessweek reported, citing an unnamed source.
This is a developing story. We'll update this story as we get more details.