Albrecht Gero Muth was arrested Tuesday night and charged with murdering his elderly wife last week, D.C. police said. Muth was taken into custody while walking in the heart of Georgetown, a few blocks from the Q Street home where her body was found.

Muth, 47, had been the only suspect in the slaying of Viola Drath, 91, a former journalist, author and Georgetown fixture. Drath was discovered unresponsive Friday morning in a bathroom at their home, and it was first suspected that she died of natural causes. Medical examiners determined Saturday that her death was a homicide.

According to three police sources, the autopsy concluded that Drath died of strangulation and blunt-force injuries. Medical examiners are expected to officially release findings Wednesday on the manner of death.

Although Muth told The Washington Post on Tuesday that he was no longer a suspect, police arrested him at 7:51 p.m., said Officer Hugh Carew, a police spokesman. Homicide detectives took Muth into custody without incident at 33rd and P streets NW. Carew said Muth was charged with second-degree murder, which implies that the slaying was not thought to be premeditated.

Two police sources said detectives would continue interviewing Muth, but were able to bring the charges after concluding that he gave no credible alibi and that there was no sign of forced entry into the home. Muth’s history of alleged violence against his wife and apparent fabrications about his life were also factors, the sources said.

Muth apparently approached one of Drath’s relatives the day she was reported dead and said that he and his wife had an agreement that he would receive tens of thousands of dollars upon her death, according to a law enforcement source familiar with the investigation.

The couple had been married for more than 20 years, a relationship that Muth said was a “marriage of convenience.” The union gave Muth, a native of Germany, access to Drath’s connections in Washington. It was also a tumultuous and sometimes violent relationship, according to court records.

Drath had filed protective orders against Muth over the past two decades, and in 2006 Muth was charged with assault after Drath told police that he hit her over the head with a chair, slammed her head into the floor and restrained her in the home so she could not report the incident. Those charges were dropped before trial because Drath declined to pursue the case.

In a statement released Tuesday night, the Drath family praised the work of the D.C. police as “excellent.”

“We are deeply saddened by the loss of our mother and grandmother, Viola Drath,” the family said. “Her intelligence, independence and grace remained intact to the end.”

Muth, in an obituary he submitted to The Post on Saturday, listed Drath’s cause of death as being from a head injury suffered in a fall and listed her date of death as Aug. 11, which was Thursday. He later said that a relative wrote that information. Her body wasn’t discovered until Friday. Police have said the cause of her death was inconsistent with a fall.

The couple hosted frequent parties in their home and across Washington, bringing together the city’s elite, including U.S. government officials, generals, foreign diplomats and media powerhouses. Muth told them that he is a general in the Iraqi army with inside access to leaders across the globe. Muth also would sometimes walk around his neighborhood in a military uniform, carrying a swagger stick.

But the Iraqi government says he isn’t a member of its military. It is one of several claims detectives are investigating as they try to piece together Drath’s slaying, police said.

Muth has no official connection to the Iraqi government or its military, according to the Iraqi Embassy in Washington. His wife’s slaying and the police investigation have exposed Muth as someone who used his wife’s legitimate accomplishments and relationships to build a life of his own that was at least partially based on dubious credentials.

Interviews with numerous Washington officials and journalists have revealed that Muth built an impressive e-mail list over the past two decades that reached the highest levels of government. Ambassadors and defense attaches attended dinners in the basement of his home under the guise of official Iraqi events. Journalists were lured with promises of hobnobbing with high-ranking members of the Iraqi military.

Muth would don official-looking Iraqi uniforms, signed his e-mails with the title of staff brigadier general and frequently contacted the media — including several Post reporters and editors — claiming inside information about the Iraq war. Some of his invitations, obtained by The Post, included the official Iraqi seal and matched typical Washington military protocol and jargon.

When he spoke to one Post reporter by telephone, he would start conversations by saying “Brigadier General Muth here” and sign off with: “We didn’t talk. Good day.”

The Iraqi Embassy said in a written statement: “We are deeply troubled by Mr. Muth’s claim of his service in the Iraqi military. He is not currently and has never been a member of the Iraqi Army. He does not represent the Embassy, its attaches, the government of Iraq, or any government institution in any fashion. In the past, the Embassy was aware of the claims made by Mr. Muth and made it clear to all concerned that they were false and demanded that they must cease.”

In e-mails to The Post, Muth dismissed the statement, saying there was no legitimate government or embassy of Iraq. He maintained that he is a general.

“[I] don’t claim to be a Staff Brig Gen, Iraqi Army. I am, as is in evidence, to the naked eye,” he wrote Tuesday. “Even MPD [the D.C. police] caught on by Sunday, I asked, what gave it away, the uniforms, the Commission on the wall, or the pictures.”

In one e-mail forwarded to The Post, he said he wrote to Vice President Biden’s office and the Pentagon’s joint staff to “relinquish” his command as his wife’s homicide investigation proceeds, and he theorized that she was killed by a professional working for Iran. When asked directly how he thought his wife died, Muth replied: “With respect, I am not a policeman.

It is unclear why Muth has crafted a role as an Iraqi military member, but the title has given him direct access to numerous high-ranking officials in Washington. Although some have dismissed his “reports” about Iraq as topical musings, others have taken their concerns to authorities. Some of his e-mails contain supposedly “classified” or “secret” information.

More than half a dozen people who attended Muth’s events said they would discuss them only on the condition of anonymity because of the ongoing criminal investigation. They said that they found Muth interesting and eccentric but that they were immediately skeptical of his claims and credentials. Two people said they contacted the FBI after meeting him, and an Iraq expert said he cautioned the White House and Iraqi officials some time ago that Muth wasn’t what he seemed.

“He’s very smooth and very effective,” the Iraq expert said. “He’s brilliant and interesting. But any person who knows this stuff can parse it and tell that it’s fake. No one has stopped him because he hasn’t done any harm. They just dismissed it as odd.”

A top Washington journalist who met Muth to discuss Iraqi issues said he quickly determined that Muth was good at digesting readily available information and then “embroidering it” by saying he had inside contact with Moqtada al-Sadr, for example.

“He told a good fable,” the journalist said. “But if you pushed on it, you pressed on it, you’d discover it was fake.”

Others found him endearing despite their skepticism. He attached himself to his wife’s causes — such as supporting the families of troops who died in the war — and seemed to genuinely want to be a part of the U.S.-Iraqi relationship.

“For all of his quirks, he seemed like someone interested in taking care of our troops and maintaining relationships between the two countries,” said a former government official. “We were always skeptical of him, but one would listen to him carefully. But Viola was the real deal. She was a great lady. It’s just sad all around.”

Staff writers Allison Klein and Alison Lake contributed to this report.