Doctors at St. Elizabeths Hospital say the District man charged in a string of hammer attacks in April is competent to stand trial but should remain in the hospital for tests, a judge said Wednesday.

D.C. Superior Court Judge Robert E. Morin called the report from doctors at the District’s mental hospital “complicated” and “unusual” during a hearing Wednesday.

In Tuesday’s report, doctors declared Michael Davis, 19, mentally competent to stand trial, saying he is capable of helping his attorneys prepare his defense. Doctors also said they were concerned that Davis’s mental issues — he has been diagnosed with schizophrenia and other mental disorders — could return or worsen.

Doctors want Davis to remain at St. Elizabeths for continued treatment and monitoring, Morin said. That’s unusual because when the hospital declares a patient charged with a crime competent, the person is usually discharged, Morin said.

Davis has been a patient of St. Elizabeths since May, weeks after he was arrested and charged with first-degree murder in the death of Denver tourist Gary Dederichs and the assault of two other people.

Police and prosecutors say Davis would sneak up behind people in Northwest Washington’s Petworth neighborhood and strike them in the head with a hammer.

Relatives told doctors that Davis’s illness was detected when he was about 9, then worsened about 18 months ago, the report said. The hospital declared Davis incompetent this summer, but doctors said then that they believed Davis’s condition would improve with medication and treatment.

At Wednesday’s hearing, Davis stood next to his attorneys from the District’s Public Defender Service. He stared ahead, his eyes half shut and his mouth agape.

Davis’s attorneys disagreed with the hospital’s latest findings. They said they planned to have Davis evaluated by their psychiatrists. Prosecutors also said they expect their psychiatrists to examine Davis.

Prosecutors said Wednesday that they expect a grand jury to return an indictment against Davis by February. Defense attorney Dana Page said Davis would not be able to enter a plea — he could plead guilty, not guilty or not guilty by reason of insanity — before Morin rules him competent. The judge agreed, and a competency hearing was scheduled for April 22.

Page then requested that Davis be released from the hospital into a shelter or halfway house so he could finish school. Morin denied that request.

Davis comes from a family of prominent athletes; two of his brothers play in the National Football League. Vernon Davis is a tight end for the San Francisco 49ers, and Vontae Davis is a cornerback with the Miami Dolphins. All three grew up in a Northwest rowhouse with their grandmother.