A senior Labor Department attorney charged with sexually assaulting a co-worker was found dead with his throat slashed early Tuesday in his D.C. jail cell, according to police officials familiar with the investigation.

Paul Mannina’s death deepens the intrigue surrounding the 58-year-old family man and respected lawyer.

His death came hours after a Superior Court judge found Mannina to be a danger to the community and ordered him held in jail — rejecting pleas from his defense attorney that he be released to seek mental-health care.

The brutal attack occurred June 5 and involved a stun gun, handcuffs and pepper spray. At first, the Northwest Washington victim told police that the attack was random, but she later pointed to a co-worker she knew for 21 years, had harbored a longtime crush on her and with whom she had planned to grab coffee in the morning and spend the day, court documents say.

D.C. jail officials would not answer any questions about the circumstances of Mannina’s death. They would not say whether he was on suicide watch or describe the process under which inmates are screened for special needs or concerns. Police are awaiting results of an autopsy to determine whether the death was a homicide or suicide. Two police officials said Mannina had a cellmate.

A 2010 photo of Paul Mannina. (Courtesy of Robert Friedel)

Mannina’s attorney and friends, some of whom testified on his behalf Monday, described the government worker — who handled claims related to pension plans — as in need of help. They pointed to a series of troubling signs from the day of the attack and said he would be unable to get the help he needed in jail.

Court documents say that as Mannina walked out of the victim’s home — after beating her so intensely that she needed surgery to implant a metal plate in her face — he told her, “I’ll just go shoot myself.”

By June 7, Mannina had been admitted to MedStar Montgomery Medical Center, said his attorney, Michael McAuliffe, although he would not say why. That day, Montgomery County police placed Mannina under arrest at the hospital and guarded his room until he was released from the hospital, on June 10, and taken to the Montgomery County Detention Center in Rockville, according to a Montgomery police spokeswoman.

D.C. police took him into custody June 12.

At his preliminary hearing Monday, there was no mention that Mannina could be suicidal, and a police detective testified that the reasons for his hospitalization were vague, based on a “change in his mental state.”

The gray-haired suspect — 200 pounds and 6-foot-3 — broke into tears with his head on the table in front of him as two of his neighbors testified on his behalf in hopes of persuading the judge to release him. About 30 of his friends gathered at the courthouse to show their support.

Robert Friedel, who showed up in court, wrote in an e-mail to The Washington Post that the judge “and the system at large failed Paul Mannina by not recognizing and acting on the need to treat him and to see that he received the medical and psychiatric help that the situation warranted.”

McAuliffe declined to describe the reasons for the hospital stay.

Through a court spokeswoman, Judge Robert I. Richter declined to comment. In court, he told McAuliffe that the issue of detainment could be revisited if he provided additional information regarding his client’s mental state and secure placement.

Sylvia Lane, a spokeswoman for the D.C. jail, declined to comment on Mannina’s death, citing the ongoing investigation. It was the second death at the jail in less than a year. In November, Michael English, a 22-year-old District man who had a history of mental illness and was charged with stabbing a friend, hanged himself with a bedsheet in his cell, authorities ruled.

Mannina had been charged with first-degree burglary while armed and third-degree sexual assault. He faced a maximum sentence of 60 years in prison.

At Mannina’s hearing Monday, the victim’s husband initially sat three rows behind Mannina’s wife, who was flanked by dozens of friends and supporters.

Mannina lived in Montgomery’s Ashton community. Residents recalled Mannina’s habit of feeding deer. They said he sometimes offered to help others with yardwork.

Richard Coffman, who lives across the street from Mannina’s home, said Mannina had served as a community association treasurer.

Coffman, who has served as the association president, said the two clashed over a proposed supermarket and whether to renovate a dam at a community pond. Mannina supported the market but opposed the dam.

Maria Schneider described Mannina as aggressive at community meetings. “He was a tall man, and he liked to be the center of it,” she said. “Sometimes it came across a little bit too — in my opinion — aggressive and trying to press something that was really not all that exciting, and he kept going with it.”

Dan Morse and Julie M. Zauzmer contributed to this report