Tweet Attacks | Suspect Held In D.C. Attacks, Including Slaying Of Denver Tourist

A man arrested in Washington D.C. late Thursday for aggravated assault is now being investigated in connection with a string of attacks, including the slaying of a 66-year-old tourist from Denver.

Michael Davis, 19, was arrested Thursday night after the latest attack, which left a 19-year-old woman in critical condition with serious head injuries, The Washington Post reports .

The attack and arrest were in the same neighborhood where Gary Dederichs, a retired nurse from Swedish Hospital Medical Center, was attacked and killed while walking alone on Tuesday night. Dederichs died by blunt force to the head.

Dederichs was the first in a two-day series of attacks in the Northwest neighborhood, but his was the only death. Detectives say Davis is suspected in connection with four attacks,all of which occurred within a 10-block radius. All of the victims were walking alone at night and suffered blunt force injuries to the head. All three surviving victims are still being hospitalized.

The suspect's brother, San Francisco 49ers tight end Vernon Davis, sent out a tweet on Thursday saying, "Just got a disturbing call from back home in washington dc. A good day gone bad! Hopefully he wasn't involved!"

Washington D.C. Police Chief Cathy L. Lanier said at a Friday news conference that Davis was near the scene of the Thursday night attack and ran away when police arrived. When police caught him several blocks away, they found a he was carrying a claw hammer in a dark-colored bag.

Davis lives in the neighborhood where all the attacks occurred.

Dederichs, a registered nurse since 1979, was an avid traveler. He lived alone in a small house about two blocks west of the University of Denver.

He was an active volunteer with A Little Help, a Denver nonprofit group that helps senior citzens stay in their homes as they get older. Dederichs was greatly loved by his elderly clients, said executive director Paul Ramsey.

"He developed such a close relationship with some who had high needs that they would set up appointments with him personally," Ramsey said. "He wasn't just doing his dues, he really enjoyed helping people."