Dawn Scott’s and Raynell Kimbrough’s relatives had been waiting for weeks, hoping Kenner police would formally accuse the man they believe killed the young couple in front of their 2-week-old child April 4.

On Friday, after nearly a month of running down leads in the case, Kenner detectives acted. They obtained a warrant for the arrest of Shaun Barnett, 28, of Avondale, on two counts of first-degree murder.

Kenner police made the announcement after Barnett, who was taken into state custody on a parole violation on the day of the killings, was transferred to their custody Tuesday.

A motive in the double killing remains elusive, Kenner Police Chief Michael Glaser said, but he believes DNA from a bloody jacket recovered at Barnett’s home is enough to link him to the crime.

Both victims’ families said they were pleased with news of the arrest.

Aside from the newborn girl, named Rayne, a 10-year-old boy named Damien and a 2-year-old boy named Zay also were inside the apartment at the time of the killings.

Scott’s mother, Ellen Scott, gained custody of the children three days after the killings. In an interview last week, she said she is now looking ahead to their long road without their mother. She hopes to move them out of Louisiana, where memories of her death will never be far away, she said.

“This was just such a senseless killing, and it’s a hurtful killing,” Ellen Scott said. “The children are never going to see their mama again.”

Damien was the first to discover his mother’s death early on the morning of April 4 in the 2100 block of Idaho Avenue, police said. He was sleeping on the ground floor of the apartment when he heard gunshots. He ran upstairs to find his mother shot twice in her bed and her boyfriend shot twice on the floor nearby.

Both died at the scene. Their infant girl, inches away from her mother in bed, was unharmed.

Damien ran to a neighbor for help, and police were called shortly before 7 a.m. Family members gathered in front of the apartment in tight clusters and wept throughout the day.

Members of both families expressed outrage when a staffer from the state Department of Children and Family Services took all three children for temporary placement in foster care.

The children remained in foster care until they were released to Ellen Scott after an April 7 court hearing.

Detectives, meanwhile, were trying to determine what had happened. There were no signs of forced entry inside the apartment.

Glaser said investigators quickly learned that Kimbrough, 31, had been seen shooting pool with Barnett the night before the killing.

Police said they also learned that a gold-colored Ford Taurus had been seen leaving the scene and that Barnett owned such a vehicle. Police also could put Barnett on the scene wearing a camouflage jacket, Glaser said.

Barnett was brought in for questioning the same night as the killings but refused to talk, Glaser said.

Barnett has a lengthy criminal record, including an arrest in connection with kidnapping and battering a woman in Jefferson Parish in a May 21, 2008, incident — charges that were later dismissed. He was convicted on charges of aggravated assault in a case involving a different woman, also in Jefferson Parish, that took place three days before the May 21 incident.

At his home in Avondale, police said, investigators recovered a camouflage jacket with blood on it. Detectives sent a sample of the blood to the Jefferson Parish Sheriff’s Office crime lab for DNA testing, and on Friday, they learned that the blood matched Kimbrough’s DNA.

Glaser said detectives obtained a warrant for Barnett’s arrest within hours.

He said police also have collected electronic evidence and surveillance video.

“The evidence of the DNA, that’s pretty compelling,” Glaser said. “Whether or not we get anything else, we feel the case now is strong enough for a conviction.”

Glaser said detectives have not yet been able to establish a motive.

People have told detectives they heard an argument of some sort the night before the killing, he said, but “I don’t know that we can pinpoint where all these three people were in the argument.”

“Why he did it, what was it for, that may be a question we never answer,” Glaser said.

The arrest came as a relief to Kimbrough’s and Scott’s families.

“My family will never forget what he’s done. We have to live with this every day. He took our hearts from us. He took a part of us,” Shaketha Kimbrough said.

Relatives said Raynell Kimbrough was a warehouse worker who adored his newborn girl.

Ellen Scott, meanwhile, is coping with the loss of her only daughter and trying to provide a new life for her three grandchildren.

Dawn Scott, 28, was a graduate of the Louisiana Army National Guard Youth Challenge Program. Ellen Scott said her daughter had always worked multiple jobs to support her children, most recently at The Home Depot.

Since the killings, Scott has moved back to her mother’s house in Avondale. On a recent weekday, Damien played video games in a shed behind the house while Zay clambered around his grandmother and Scott’s sister cradled Rayne.

All three children are living crowded inside the house, which has always served as a haven for the Scotts in tough times. “When you fall down, this is where you come,” Ellen Scott said.

Scott said her dream is to raise enough money to move the children to Mississippi. “I don’t want Damien to keep having to relive this once he goes back to school,” she said.

Even then, Scott said, she knows things will never be the same.

“There’s nothing like a mother’s love,” she said. “I can love them all I want, but it’s nothing like their mama.”

Ellen Scott has asked anyone interested in contributing to the children’s living expenses to visit http://www.gofundme.com/22evdyc or to make a donation in the name of Dawn Ellen Scott at any area Capital One Bank.