Unsolved Mysteries Wiki

Maria Armstrong

Real Name: Maria Catherine Armstrong
Aliases: Sandy
Wanted For: Murder, Theft
Missing Since: November 11, 1988


Details: Maria Armstrong grew up in south New Jersey. Her boyfriend, Robert Neil "Ron" Argenti, graduated at seventeen and joined the National Guard. In 1984, he moved to Mesa, Arizona, and began working for McDonnell-Douglas. At the same time, Maria, still in New Jersey, began acting strangely. She began slipping into a world of delusion and paranoia. At first, her parents feared that she was using drugs. They had her committed to the state mental hospital. However, doctors soon diagnosed her as having paranoid schizophrenia. Ron convinced her to move to Arizona and live with him.
In June 1988, Maria moved to Mesa; Ron hoped that he could help her with her problems. His family was concerned for their safety since she had been in a mental institution. For the first few weeks, however, she seemed to be adjusting to living there well. Then, when Ron started working the graveyard shift, her paranoia flared up again since she was alone for long periods of time. Also, a neighbor in their apartment complex began supplying her with drugs. She accused Ron of plotting against her and began to physically attack him. When his family heard about her problems, they tried to convince him to take her to a mental hospital.

Ron Argenti

Finally on November 8, 1988, Ron had had enough of Maria and told his sister that he was going to have her go back to New Jersey. The next day, she drove to a Navajo reservation called Bitter Springs. She took his car and tried to sell it; she was also going by the name "Sandy". She asked some residents where she could get it painted. They noticed that she was behaving strangely. She was seen talking to herself, and even walked into some houses uninvited. She also asked one woman to dye her hair. The next morning, the Arizona Highway patrol was called to a house in Bitter Springs. She had left the car there and the residents believed that it was stolen. The officer later found her hiding in a nearby house and questioned her. He did not have any reason to hold her, although he felt suspicious about the incident.
Four days later, on November 14, the maintenance man at Ron's apartment noticed a stack of newspapers in front of his door. He and the manager went inside and found his body hidden under several blankets and pillows. He had been killed by several blows to the head, and a sledgehammer was found next to him. The autopsy revealed that he had also been stabbed once in the side with a wood-handled knife. Authorities believe that while he was sleeping in a sitting position on the couch, Maria beat him to death, and covered his body. Afterwards, she took his car to Bitter Springs. She was last seen on November 11, 1988, hitchhiking 260 miles north of Mesa. The police are looking for clues as to where she is.
Extra Notes: This case first aired on the November 29, 1989 episode.

Maria prior to her 2005 release

Results: Captured. After this case was re-aired, a viewer contacted the FBI, stating that Maria was living in the Memphis, Tennessee area. The viewer said that she was going to be at the airport on August 3, 1990. The FBI went there and was able to locate and arrest her without incident. During her time on the run, she had changed her appearance by dying her hair blonde. She had told authorities that she was planning to fly to New Jersey to be reunited with her family.
Two weeks after her arrest, Maria was returned to Arizona to face first-degree murder charges. However, while waiting to determine her mental state, she decided to plead guilty to second-degree murder and was sentenced to fifteen years in prison. She was released in 2005 after serving thirteen years.