Early on the morning of July 19, 1984, police arrived at a south Minneapolis apartment building to find a woman standing in the hall, her face half covered in blood.

"Hurry up!" another woman shouted, according to a Star Tribune report from the time. "They're killing him!"

Police found Robert A. Miller stabbed to death in the apartment. A trail of blood, which investigators surmised belonged to the killer, led down the hallway and out the back door.

Almost 40 years later, investigators say they have found the killer.

The Hennepin County Attorney's Office has charged 66-year-old Matthew Russell Brown of Ingleside, Ill., with second-degree murder and first-degree burglary in connection with Miller's decades-old slaying. The linchpin in the case, they say, was a disposable cup discarded by Brown that contained DNA matching the blood at the scene.

According to the recently unsealed charges:

At 2:30 a.m. that day in 1984, police arrived at Miller's apartment at 3209 Girard Ave. S., where the two women in the hall said a man armed with a knife had broken into the building and attacked them.

Officers found Miller dead with "stab wounds to his face, head, chest, back and shoulders."

Investigators collected blood from the kitchen floor and a doorknob, likely from the suspect inadvertently cutting himself.

In 2018, the Minnesota Bureau of Criminal Apprehension used the blood samples to establish a DNA profile for a suspect, and genealogists determined the blood belonged to Brown. But they failed to procure a new DNA sample from him to prove their finding — until this past March. That's when investigators recovered the cup containing the DNA that matched blood from the 1984 crime scene.

Brown was being held at the Hennepin County jail on a $1 million bail and scheduled to appear in court Monday morning.