LITTLE ROCK, Ark. (KTHV) - After weeks of silence, Little Rock Police Department detectives say they have finally solved the December murders of a woman and her two young children.

They announced Michael Collins as the second suspect Friday, Jan. 12 in the murder of Mariah Cunningham, her daughter, Alayah Fisher, 5, and son Elijah Fisher, 3.

Collins, 25, is the brother of William Alexander, who was arrested Monday in Little Rock. Alexander is being held in the Pulaski County Jail without bond for three counts of Capital Murder. Collins will face the same charges when he returns to Little Rock. He is currently in federal custody in the Federal Transfer Center, Oklahoma City.

Captain Russell King, the commander of the Little Rock Police Department's (LRPD) Major Crimes Division, said Collins was pegged as a suspect shortly after the bodies of Cunningham and her children were found inside their Little Rock apartment on Dec. 5.

King said tips from the community led them to believe Collins had fled to Chicago.

“Furthermore, it was discovered that Mr. Collins had some outstanding federal probation violation warrants,” King said.

Members of the U.S. Marshal Service arrested Collins at a home in Chicago on Dec. 8 for those federal warrants. Alexander was arrested one month later, and on the same day, a judge issued murder warrants against Collins, as well.

“It is the very hard work of a collective group of professionals that are working very hard every single moment of the day, to bring safety and return safety to our streets,” said Little Rock Mayor Mark Stodola.

King and Police Chief Kenton Buckner both said it took detectives, the state crime lab, prosecutors, the U.S. Marshal Service and information from the local community to complete the case against him.

“The city manager’s office put up the $50,000 reward,” Buckner mentioned. “That certainly helped generate a lot of energy, a lot of calls, a lot of information.”

“They’re talking to us. They’re helping us with this investigation. That’s critical,” King added. “That’s everything to us. So, we want to applaud all parties involved.”

LRPD officials had been quiet about most of the details of the investigation, with department spokesmen adding that detectives made a point of not giving them any information. One significant piece that has not been made public thus far is a motive for the murders.

“You have to understand: this is an open investigation,” King explained. “We have to protect the integrity of the investigation, and we don’t want to compromise any potential jurors out there.”

Family members told THV11 that Collins and Cunningham were friends and former roommates.

“It puts an accent point on an issue, the issue of domestic-related violence, that we have seen continually as a problem in our community,” Stodola said. “And it’s something that — as a community — we need to continue to reach out to people to help us with, as it relates to those issues. It’s a real issue above and beyond some of the other kinds of issues that we’ve seen in our city.”

King said there is no timeline for Collins’ return to Arkansas. Federal prosecutors could either bring him back soon, or force him to stand trial for his other charges first.

Alexander has pleaded not guilty.