The arrest warrant for Raymond Clark III, released Friday morning, makes public for the first time the details of how authorities came to suspect Clark in the murder of Annie Le GRD ’13, and reconstructs Clark’s activities the day Le disappeared and the days after.

Clark was arrested Sept. 17, nine days after Le was first reported missing and five days after her body was found in a wall cavity in the basement of 10 Amistad St., the research building where both Le and Clark worked. As investigators searched the building, combed through electronic key card swipe records and watched video surveillance footage over the course of the investigation, they uncovered a trail of DNA evidence that pointed to the animal laboratory technician. And repeated encounters with Clark himself only fueled their suspicions. Clark has yet to enter a plea.

[ydn-legacy-photo-inline id=”9153″ ]

Though police began interviewing Le’s family, friends and colleagues soon after her roommate, Natalie Powers GRD ’13, reported her missing on the evening of Sept. 8, nothing appeared to involve Clark until Sept. 10. That day, pharmacology postdoctoral fellow Rachel Roth, who worked with Le, approached Yale Police Officer Sabrina Wood, showing her a box of Wipe-All hygienic wipes with what appeared to be splattered blood sitting on a steel pushcart in G13, one of the laboratory rooms where Le had worked, prompting Wood to call FBI agents to the scene.

As she waited for the FBI to arrive, Wood watched Clark come in and leave G13 “several” times, according to the affidavit. He walked over to the pushcart and shifted the box of wipes from one side of the cart to the other, turning it so the blood splatter faced away from Wood, then leaned on the cart as he made small talk with the officer. Later that day, Clark began scrubbing a drain in G13, even though Wood said the drain did not appear to need cleaning.

There were other encounters between investigators and Clark, too: Clark came up to Yale Police Officer Jennifer Garcia on Sept. 10, according to the affidavit, and volunteered information, saying he had known Le. Clark told Garcia he had seen Le working in G13 at about 10:30 a.m. the morning of Sept. 8 and later saw her leaving the building at 12:30 p.m. Video surveillance records did not show Le leaving 10 Amistad at any time after she entered it that day.

As part of a series of interviews with Le’s co-workers, investigators spoke to Clark on Sept. 10 and learned that he had been assigned to take care of the animals in three laboratory rooms, including G13, on the day of Le’s disappearance. Clark and Le had known each other for at least four months, Clark told FBI agents, but never socialized or saw each another outside of work. During the interview, agents also asked Clark about scratches on his face and upper left arm, which he said had come from a cat.

And while the FBI asked the public for information about Le’s disappearance, displaying Le’s photograph on billboards and setting up a tip line, other FBI team members were gathering objects from the building and Le’s home. They would eventually amass a collection of about 250 pieces of evidence, including the box of Wipe-Alls and an extra-large lab coat with red stains found in a recycling bin in 10 Amistad. DNA on the box and lab coat matched the DNA on toiletries taken from Le’s house, and lab testing also revealed DNA on the lab coat from an unknown male.

Even as police collected bloody evidence, they insisted that there was no evidence of foul play and that there were no suspects. But when state crime investigators found bloody clothing during a search of the basement of 10 Amistad on Sept. 12, police officers confirmed that they had declared the building a crime scene. The items found included a rubber glove, a white sock, a pair of Vikings-brand work boots labeled “Ray-C” on the back and one blue short-sleeved hospital scrub shirt, all stained with what appeared to be blood. Through chemical analysis, investigators found blood-like stains and spray patterns that had been cleaned off the walls of G22 and G13, later confirmed to be blood.

The next day, an odor “similar to that of a decomposing body” struck investigators inspecting the locker room in the basement of 10 Amistad, according to the warrant. Cadaver dogs were brought to the scene and immediately detected a decomposing body. Shortly after 5 p.m., investigators found Le’s body concealed in a wall behind the toilet in a mechanical chase, a compartment in the wall that runs from the basement to the roof. She was wearing surgical gloves with her left thumb exposed, with several items surrounding her body in the wall cavity, including a green-inked pen, a stained lab coat and a sock — one that matched the blood-stained sock found the day before.

On Sept. 15, police obtained a search and seizure warrant to collect mouth swabs, body hair, fingerprints and fingernail clippings from Clark. DNA tests showed that stains on the sock had a mixture of Le’s and Clark’s DNA and that the pen contained Le’s blood, while Clark’s DNA was inside the pen cap and on the barrel. Over the next few days, more hair fibers and blood stains turned up in various lab rooms.

FBI agents conducted a detailed examination of when and where Clark’s security keycard was used in the building before and on Sept. 8, finding a flurry of activity. While he used the keycard to access G22 three times and once to access G13 in the 12 days between Aug. 27 and Sept. 8, he used it 11 times to open G22 and five times for G13 on Sept. 8 alone. Clark apparently moved between rooms a total of 55 times between 10:40 a.m. and 3:45 p.m. on the day Le disappeared. Investigators also found that Clark’s keycard was the only one used to access G22 — where the traces of blood were found on the walls ­— after Le swiped into 10 Amistad that morning.

The warrant, submitted with the affidavit, was signed by a judge, and Clark was arrested at a Cromwell, Conn., motel in the early morning of Sept. 17.