Lindsay Nichols made a desperate call for help to 911 early in the morning of June 21. A man was outside her car threatening her.

The operator could hear Nichols screaming while a man in the background demanded that she open her mouth so he could place a gun inside of it. Then the line went dead.

Eight minutes passed between when Nichols made her call and when the dispatcher sent a police officer who was three blocks away to the scene.

Nichols was found shot dead in the trunk of a burned-out car at the corner of Lake Forest and Michoud boulevards more than two hours later.

“My daughter called thinking she was going to get help,” said Jolene Dufrene. “Instead, they got the call, no one was there, and that was it.”

Drawing hard conclusions from the Nichols case is complicated. Not only did it take eight minutes to dispatch an officer, but the 911 operator made what could have been a fatal omission: She never told responding officers about the gun. Two officers, unaware of the urgency involved, spent about 15 minutes looking for Nichols in a New Orleans East parking lot, then marked the call as “unfounded.”

Still, the case does underscore one dimension of the dramatic increase in police response times over the past five years. Before cops even get in their cars, they must be dispatched. And the time it takes to dispatch officers to crime scenes in the first place has risen significantly, according to a New Orleans Advocate/WWL-TV analysis of millions of 911 calls.

For high-priority Code 2 calls such as the one Nichols made, the average time between a call and a dispatch has risen from three minutes, 39 seconds in 2010 to 12 minutes, 21 seconds today — increasing in tandem with a decline in the number of NOPD officers.

Nichols, 31, was a Louisiana native who was visiting from Texas, where she worked as a timekeeper for a construction company. She was visiting friends and her young son.

Her companions said she went out with them to a nightclub in New Orleans East on the night she was killed. At the club, Nichols encountered Thayon Samson, 30, and got his number.

Between 4:11 a.m. and 4:18 a.m., Nichols made two calls to Samson, according to an arrest warrant signed by Detective Robert Barrere. Somehow, Nichols wound up in the parking lot outside of Samson’s apartment in the 6000 block of Chef Menteur Highway, near Downman Road.

The exact sequence of events that followed is murky. But according to the arrest warrant, as Samson stood outside of Nichols’ Honda Accord, he began accusing her of giving his address to someone else.

Samson had a handgun, police believe. As the call went on, Nichols “moaned and sounded as if she were being attacked.” Her mother said she was told that the call lasted for about seven minutes.

Three blocks away in the 6300 block of Chef Menteur Highway, a 7th District officer was conducting a routine traffic stop. Nichols’ call for help was first made at 4:48 a.m. But the officer was not sent to her aid immediately. According to NOPD spokesman Tyler Gamble, no officers were available for the call at the time. Finally, eight minutes later, two police units were sent to the scene.

“I don’t understand why they wouldn’t dispatch right away. That’s what I don’t understand the most,” Dufrene said. “She was frantic, from what I understand, on the phone. That was a desperate call.”

The eight-minute dispatch lag in Nichols’ case appears to have been exacerbated by another mistake. The dispatcher, Treva Sip, allegedly never told police about the gun, or the full extent of the threatening scenario.

“The operator did not provide the details of the initial complaint to the officer, including the mention of the gun, so the officer was unable to locate the complainant based on the details that were given to him,” Gamble said. “He was not able to locate a scene, a victim, and he left.”

Gamble said Sip, who had been on the job for 16 months, never recorded when the first officer actually arrived at the scene, so it was difficult to know the initial response time.

But the police spent at most 14 minutes looking into her call. Nichols’ call for help was marked as “unfounded” at 5:10 a.m. By 5:13 a.m., according to dispatch records, the lead officer on the scene had moved on to a traffic stop.

The number of dispatches marked as “unfounded” has risen from 8.1 percent of calls in 2010 to 16.9 percent today.

Gamble said that after Nichols was found dead, the Police Department launched an investigation into how the call was mishandled. Sip resigned while under investigation on Sept. 23. She said her reason for leaving the department was to “attend school,” according to Civil Service Commission records.

Sip, 35, did not return a request for comment Thursday.

A security guard for the abandoned Six Flags New Orleans site spotted Nichols’ car at the corner of Lake Forest and Michoud boulevards about 6:17 a.m. Witnesses told police they saw a man standing over the car’s trunk about 7 a.m. Fifteen minutes later, the trunk was on fire. Responding firefighters discovered her body inside.

Samson was later taken into custody and remains in jail on $2.5 million bail. The District Attorney’s Office has not yet charged or indicted him with murder.

Dufrene is now raising her daughter’s young son. She is haunted by the thoughts of his mother’s final moments.

“It’s hard. Just knowing that she might, could’ve been saved,” Dufrene said. “The way she died was so sad. That’s the hard part. It was so brutal and vicious. Such cruelty.”

Dufrene praised the work of NOPD detectives such as Barrere. But she wishes it had never been necessary.

“The detectives did such a great job, and they found the guy, and that was great — using DNA and all that,” said Dufrene. “But maybe (the police) could have found him that night.”

Staff writer Jeff Adelson contributed to this report.