Portland police would not say Wednesday how they connected a former South Portland man to a 2016 homicide or what new information led detectives to pursue an indictment this year, more than four years after the killing.

Aristotle Stilley Portland Police department

Aristotle Stilley, 23, is being held at a Sacramento, California, jail until his first scheduled court appearance Thursday in Sacramento Superior Court, where he faces extradition to Maine. But there has been no public release of information describing the probable cause supporting the murder warrant or any description of how police linked Stilley to the crime and secured the August grand jury indictment. The indictment has been sealed.

Portland police spokesman Lt. Robert Martin said detectives in Maine had been working with police in Sacramento to find Stilley since his indictment in August. But a Sacramento police spokesman said it was a random, run-of-the-mill traffic stop that led California officers to discover the Maine arrest warrant.

David Anderson

“They literally just stopped the car. He was driving,” said Sacramento officer Karl Chan, a spokesman for the department. “A records check revealed the warrant and they took him into custody. It was literally just a routine enforcement stop.”

Stilley is charged with the murder of David Anderson, 36, who was shot inside a third-floor apartment on Gilman Street on March 15, 2016. Anderson was one of four guests at the apartment, in addition to the full-time resident.

At first, police had little to go on, Martin said. A search warrant for the apartment unsealed in 2016 described how the gunman entered the apartment complex with his face mostly obscured by a hooded sweatshirt and a mask covering the lower portion of his face. After the gunman knocked on the apartment door, he stood with his back to the door’s peephole.

When Anderson and another man went to answer the knock, the gunman opened fire through the closed door, fatally wounding Anderson and injuring the other man. After the shooting, the gunman was seen on surveillance footage picking up shell casings from the carpet that could have later been used as evidence, and leaving the building.

“(With) the whodunnit cases, it takes a lot of work,” Martin said. “There’s a lot of moving parts.” He added later: “We spent a lot of hours, we used a lot of resources, we got assistance from a lot of agencies.”

Martin refused to discuss when Portland detectives focused their attention on Stilley, or when they confirmed he was in Sacramento. Martin also declined to discuss what the alleged motive may have been, or what relationship, if any, Stilley had to the people inside. Martin also would not say whether Anderson was the intended target of the shooting.

Martin said more information may be released when Stilley returns to Maine and is arraigned on the murder charge, but there is no guarantee that any description of the investigation or links to the shooting will be made public before a future trial.

Around the time of the shooting, Stilley had no permanent address and was couch surfing, although his family had lived in South Portland, Martin said. Martin said Stilley was considered homeless at the time of his arrest in California, and it’s unclear if he has family or employment ties to Sacramento.

Although it’s unclear when Stilley moved from Maine to California, records from the Sacramento courts indicate he was in the city as early as 2018, when he was arrested twice in two months, first in November 2018 for carrying a concealed knife, and then in December 2018 for misdemeanor methamphetamine possession. He pleaded no contest to the drug charge, and was placed on three years probation.

Stilley had another criminal case in 2019, according to court records, when he was charged with misdemeanor methamphetamine possession, resisting arrest, and possessing pepper spray, which is regulated with criminal penalties in California under certain circumstances.

Maine investigators were prepared to move forward with the case against Stilley in the spring, Martin said, but the global pandemic shutdown much of the Maine court system, delaying the presentation to a grand jury. Martin declined to say what break in the case led investigators to pursue charges now, more than four years later, and said that to go into too much detail could endanger Stilley’s right to a fair trial.