A strangely dressed individual is believed to have murdered a 92-year-old millionaire property developer in his Southern California beachside residence, before engaging in a lengthy standoff with SWAT teams, as reported by local authorities.

Hermosa Beach police reported that they responded to a residence on the 500 block of The Strand just after 12:30 p.m. on Saturday for a welfare check. Concerns arose as the elderly homeowner had not been seen for several days.

What began as a standard welfare check quickly turned into a tense situation. Officers, accompanied by a property manager, entered the house only to find a non-compliant person who claimed to be armed and subsequently barricaded himself inside, according to the Hermosa Beach Police Department.

SWAT teams from various agencies, along with crisis negotiators, were deployed to the scene and worked diligently for several hours to ensure a peaceful resolution. The individual was eventually detained approximately seven hours following the initial call.

The suspect appeared in an unusual ensemble, wearing a black suit, tie, fedora, and sunglasses, and surrendered to law enforcement after the prolonged standoff. (Photo credit: Kevin Cody/EasyReaderNews.com)

After securing a search warrant, officers discovered the lifeless body of an adult male within the home.

The victim was identified as 92-year-old Demetrius Doukoullos, a longtime developer who lived alone at the beachfront property, according to the Los Angeles County Medical Examiner. The office lists the cause of death as deferred, pending further investigation. The Los Angeles County Sheriff’s Department Homicide Bureau has taken over the investigation.

Law enforcement sources told NBC4 Los Angeles the victim’s body showed signs of decomposition when it was discovered inside the residence.

Los Angeles County jail records identify the suspect as Elanor Beaulieu, 39, who is listed as male. The suspect is being held on suspicion of murder with bail set at just over $2 million. Records also show prior bookings under the name Robert Phillip Simmons.

Beaulieu was arrested while wearing a black suit and tie, a black fedora and black sunglasses.

Elanor Beaulieu was arrested while wearing a rather unusual outfit reminiscent of the Blues Brothers.

The relationship between the suspect and the victim remains unclear, and investigators have not publicly identified a motive.

In a neighborhood Facebook group, a person claiming to live in the building said concerns were raised after the resident had not been seen for about a week and a strong odor was coming from the home. Those claims have not been independently verified.

Fox News Digital has reached out to the Los Angeles County Sheriff’s Department and the Los Angeles County Medical Examiner for additional details, including the victim’s official identification, cause of death and any known connection between the suspect and the victim.

Stepheny Price covers crime, including missing persons, homicides and migrant crime. Send story tips to stepheny.price@fox.com.