For more than a month, the investigation into Taherah Ghassemi’s disappearance inched along as detectives patiently hunted for the Baton Rouge woman who disappeared in early April.

And then the big break came.

Within about 24 hours over the weekend, Taherah Ghassemi’s body was found buried in a rural, wooded area about an hour’s drive northeast of Baton Rouge. Soon afterward, authorities arrested Taherah Ghassemi’s ex-husband and three men accused of collecting $10,000 from him in exchange for abducting, killing and burying his ex-wife.

The extraordinary turn of events occurred in large part because of cellphone location records collected by Sheriff’s Office detectives. Using data obtained from a phone of one of the men who was arrested, Tyler Lee Ashpaugh, detectives traced the location of his phone from Taherah Ghassemi’s residence to the place where her car was found destroyed, and ultimately, to an area near the hole where she was found Saturday, wrapped in a blanket stolen from her home, according to a Sheriff’s Office report.

In addition, phone records showed Ashpaugh called Hamid Ghassemi, Taherah Ghassemi’s ex-husband, a few hours after she disappeared. Cellphone records indicated Ashpaugh also went to the ex-husband’s home off Old Hammond Highway in the early morning hours of April 12, not long before Taherah Ghassemi’s Jaguar sedan was found torched on a road surrounded by fields a couple blocks north of South Choctaw Drive in Baton Rouge, the report says.

Capt. Todd Morris, the Sheriff’s Office homicide commander, declined on Monday to go into specific detail about how authorities found Taherah Ghassemi’s body buried on wooded property in rural St. Helena Parish, just north of Pine Grove.

“But obviously,” Morris said, “it started with some cellphone records.”

Taherah Ghassemi’s abduction and killing occurred about two months after she and her ex-husband finally reached a settlement in a decadelong divorce battle. Hamid Ghassemi, who owns the Import One and Import One Elite car dealerships on Airline Highway, agreed to pay his ex-wife more than $1 million as part of the settlement. She also was awarded two of his homes — one in Baton Rouge and another in Lafayette.

The settlement marked the end to a dispute that began, at least legally, when Taherah Ghassemi emigrated from Iran — where the couple was married decades ago — to the Baton Rouge area. She filed for divorce from him in 2005 in the 19th Judicial District Court, where the matter wrapped up for the most part with the settlement in February.

According to authorities, though, Taherah Ghassemi was killed before she lived long enough to enjoy her first few months in America not embroiled in bitter divorce proceedings.

Sheriff Sid Gautreaux, flanked by several local and state law enforcement leaders, said Monday it took “around-the-clock, 24/7 investigative efforts” to find the missing woman’s body and arrest her ex-husband in the alleged murder-for-hire killing.

For five weeks, since Taherah Ghassemi was reported missing on the morning of April 13 by her son, authorities searched for her, hoping for the best but fearing the worst.

“While I hoped she was still alive, all the evidence indicated she was not,” Gautreaux said. “We can now at least give her family some answers about what happened to her, and most importantly, we have those that did it behind bars.”

Authorities on Sunday booked Hamid Ghassemi, 64, into the East Baton Rouge Parish Prison on counts of principal to first-degree murder, principal to second-degree kidnapping, solicitation for murder and principal to arson. Deputies also booked Ashpaugh, 20; Skyler W. Williams, 17; and Daniel Humberto Richter, 33, into Parish Prison on one count each of first-degree murder, second-degree kidnapping and arson.

On Monday morning, State District Judge Richard Anderson ordered all four men to be held in jail without bail.

C. James Rothkamm Jr., Hamid Ghassemi’s attorney, declined on Monday to comment on his client’s arrest. Attempts to reach representatives for Ashpaugh, Williams and Richter on Monday were unsuccessful.

No one answered the door at Ashpaugh or Williams’ homes, both of which are in Denham Springs, nor was the door answered at Richter’s home in Walker.

Messages left for Hamed Ghassemi, the 37-year-old son of Taherah and Hamid Ghassemi who lived with his mother in Baton Rouge, were not returned.

Dr. Beau Clark, East Baton Rouge Parish’s coroner, said Monday that Taherah Ghassemi died from a gunshot wound to the head.

While many details emerged in the past two days about the events leading up to Ghassemi’s disappearance and death, it still was not clear Monday who fatally shot her, nor was it clear when exactly she was killed.

According to a Sheriff’s Office report, Ashpaugh, Williams and Richter abducted Ghassemi from her North Laurel Creek Court home sometime after 8 p.m. on Saturday, April 11. Next, they stuffed her into the trunk of her Jaguar sedan and drove out to St. Helena Parish, the report says.

At some point before they buried her, she was shot.

Although it’s not clear exactly when they did so, the report says all three men went to Hamid Ghassemi’s home either right before or soon after she was killed. He gave the trio $10,000 to split among themselves in exchange for the hit, the report says.

Also at some point the night of April 11 or early in the morning on April 12, the three men took Taherah Ghassemi’s Jaguar to the 9600 block of Chalma Avenue and lit it on fire with gasoline provided to them by her ex-husband, the report says.

With time working against them, the report says, investigators on Saturday “identified the cellular telephone coordinates of a location off La. 16, in St. Helena Parish,” where Ashpaugh’s phone was near on the afternoon of April 11 — hours before Taherah Ghassemi disappeared. Authorities trekked out there, and after searching for some time, “located what appeared to be a freshly dug area,” the report says.

Authorities quickly obtained a search warrant to begin digging, and before long, “detectives observed a light-colored comforter with a reddish stripe-like pattern wrapped around the body of a deceased female,” the report says.

It was the same blanket missing from her home after she was abducted.

Joanie Brocato, director of the Louisiana State Police Crime Lab, said forensic analysts received samples of evidence from the scene Saturday about 8:30 p.m.

By 2:45 a.m. on Sunday, a DNA test confirmed the dead woman was Taherah Ghassemi.

Col. Mike Edmonson, the State Police commander, said Monday the facts in this case “will speak for themselves.”

“It was cold. It was dark. It was deep,” Edmonson said, describing the statements provided to detectives by at least two of the men who were arrested. “There was no remorse,” he said.

Morris, the Sheriff’s Office homicide commander, said there didn’t appear to be any connections to the property where Ghassemi was found and the men who were accused of killing her. Morris also said he would not reveal whether detectives knew what kind of gun was used to kill Ghassemi, nor whether the murder weapon had been located.

Richter, the oldest of the trio accused of carrying out the alleged murder-for-hire, once worked at one of Ghassemi’s car dealerships, and Ashpaugh and Williams were described as associates of Richter, Morris said.

Richter and Williams have known each other for at least a couple of years, because Livingston Parish court records indicate they were involved in an altercation at the Laguna Beach Bar in Denham Springs in July 2012.

After the incident, Richter was arrested on counts of disturbing the peace, contributing to the delinquency of a minor and entering or remaining in a place after being forbidden, though the District Attorney’s Office later rejected or did not prosecute all the charges. Because Williams was only 15 at the time, the matter would have been handled in Juvenile Court and would not be considered public record.

In district court records, he was identified as “S.W.” with a matching birthday.

Now 17, Williams is awaiting trial in Livingston Parish on one count each of possession of marijuana and possession of drug paraphernalia.

On Monday, Gautreaux lauded the multi-agency effort that led to the arrest of Hamid Ghassemi, Ashpaugh, Williams and Richter. State Police, the St. Helena Parish Sheriff’s Office and the Livingston Parish Sheriff’s Office worked with the East Baton Rouge Sheriff’s Office to locate and apprehend the four men.

“Though extremely tragic,” Gautreaux said of the abduction and killing, “we are glad that we can at least bring some closure to her family.

“And bring those responsible to justice,” he said.

Advocate staff writer Joe Gyan contributed to this report.