On that March day more than a year ago, they were seeking "any evidence associated with the delivery and death of a newborn child whether alive or deceased," according to the affidavit for the search warrant.
What they found buried in the back yard - the skeletal remains of a fetus - led to the indictment last month of a 43-year-old woman who lived there. Michelle Frances Roberts is accused of self-aborting in the third trimester of her pregnancy. She was arrested March 29 this year on felony charges of "producing abortion or miscarriage."
The rarely invoked law, written in 1950, prohibits giving a pregnant woman a drug or taking any action "with intent to destroy her unborn child."
Roberts, who remains in jail in Chesterfield, has denied the charges. According to the police, she told investigators she gave birth to a baby boy in the house, but he died afterward, and she buried him in the back yard.
Police and prosecutors have revealed little about the evidence that led to the unusual charge against Roberts, who court records show has a history of drug use.
Commonwealth Assistant Attorney Shawn Gobble refused to comment on the case. Roberts' defense attorney, H. Pratt Cook III, did not respond to repeated requests for comment. She is scheduled to appear in court Monday for a status hearing on the case, which has alarmed women's rights advocates in Virginia.
"It is unclear from the questionable, selective release of information by the Chesterfield police exactly what happened here," said Gail Deady, the Secular Society Women's Rights legal fellow for the Virginia ACLU. "But it appears that this is another example of overreach and targeting of a pregnant woman in an attempt to shame and punish her for her circumstances."
But a neighbor who saw the police cars arrive on their street said the discovery of the remains near a big tree in the back yard sent chills through her body: "It wasn't right. She should have gone to a doctor. If you don't want the baby, you go to the doctor."
The law has been used at least once before by Virginia authorities to charge a woman with harming her unborn child, according to the Richmond Times-Dispatch. In 2005, a Suffolk woman was prosecuted for shooting herself in the abdomen on her due date and then blaming her injury on a man. But a circuit court judge dismissed the charge, saying the law was not intended to punish expectant mothers. It was aimed at the actions of others.
Repeated efforts by state legislators to pass a law making it a crime for a pregnant woman to self-abort were unsuccessful.
Deady said she is concerned about the repercussions of the Roberts prosecution.
"It could mean anyone who has a miscarriage could be subjected to an investigation by police and thrown in jail," she argued.
It was the mother of Michelle Roberts's boyfriend, Danny Coppola, who tipped police off to the missing baby, according to court records.
Before Coppola went to prison in 2015 for violating his probation in a 2011 forgery case, he told his mother, Linda Castillo, that Roberts was pregnant with a baby boy, according to police. The couple also have an adult daughter, Lauren Coppola.
Roberts, police said, acknowledged to Castillo that she was five months pregnant. Castillo asked Roberts which doctor she was going to. "Michelle told her that she was going to check with the doctor at the methadone clinic because they would not judge her," police said.
Since 2012, Roberts had been visiting the Richmond Southside Treatment Center, where she received low doses of methadone four times a week, police said. Detectives said the clinic director verified Roberts was a regular patient at the clinic, but he had no record of Roberts ever being pregnant.
By Castillo's calculations, her new grandchild should have been born around September or October 2015. But she never received an announcement.
Castillo told police she next saw Roberts in October 2015 at a hospital where Lauren Coppola had been admitted after a car accident. At the hospital, Castillo asked Lauren about her mother's pregnancy, police said.
Coppola, now 21, told her grandmother that she "needed to talk to Michelle about that," police said, "and that she didn't want to be involved."
Castillo walked into the hospital hallway, where she saw Roberts. She noticed Roberts no longer appeared to be pregnant, police said.
Roberts told Castillo, "This isn't anything we need to discuss here."
About a month later, Coppola and her boyfriend, Dylan Kidwell, had an argument at the house on Philbrook Road in Chesterfield, where they lived with Roberts and Roberts's stepfather, police said. Castillo arrived during the tumult.
At one point, Kidwell shouted something at his girlfriend's mother that made Castillo suspicious, police said.
"You better watch yourself," Kidwell yelled at Roberts. "Because I know what's buried in the back yard."
Castillo asked Roberts what was buried in the back yard.
"Michelle told Linda that the baby had been born in the house," according to police.
"She said the baby took one breath, at which point she passed out," police said. "Michelle said that Lauren woke her up and told her that the baby died and that she and Dylan dug a hole in the back yard and buried it."
Castillo died on March 12 last year, five days after police executed a warrant to search the back yard of the house on Philbrook. Castillo was 56.
Chesterfield County police said Lauren Coppola and Dylan Kidwell have not been charged in the case. Neither could be reached for comment.
"At this time Michelle Roberts is the only one charged in this matter," said Capt. G. Netherland, a spokesman with the Chesterfield County police.
Before his mother's death, Danny Coppola, who is incarcerated at the Augusta Correctional Center in Craigsville, Virginia, wrote three letters to her in which he mentioned "Michelle's baby," police said.
The police search of the home and the back yard, court records say, yielded: "human remains; two Samsung galaxy cellphones; a disc thumb drive; a white tablet; and a journal."
The house, where pink azalea bushes are blooming in the front yard, is now for sale.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)