Three alleged killers were held without bail in separate arraignments at different courts for unrelated Boston murders, Suffolk County District Attorney Daniel F. Conley said today.

The men accused of killing 48-year-old Jewell Alsop on Feb. 26 in Dorchester; 15-year-old Soheil Turner in Roxbury on May 7; and 20-year-old Antoine Perkins in Dorchester three summers ago were all arraigned on murder charges today. None of the victims or cases was related to another, Conley said, but each was the subject of vigorous investigation by Suffolk prosecutors and Boston Police homicide detectives.

In Roxbury District Court this morning, Assistant District Attorney Julie Higgins told Judge Kenneth J. Fiandaca that FITZHUGH NEWTON III (D.O.B. 3/26/59) had been identified through DNA analysis as the man who raped Jewell Alsop and strangled her to death in the back of a truck earlier this year. Newton was arrested June 29 as he served a six-month sentence for violating his probation on an unrelated offense.

Higgins said that Boston Police scouring the scene for evidence recovered biological evidence from which they were able to develop a DNA profile. When they submitted that profile into the state’s Combined DNA Index System, she said, it matched that of Newton. As a felon with convictions for kidnapping, assault with intent to rape, and other offenses, Newton had in the past been compelled to submit a sample to the CODIS database; it was that sample that matched the DNA recovered from the murder scene.

Fiandaca ordered Newton held without bail. Newton will return to court on Aug. 10 with attorney Matthew Kamholtz.

Meanwhile, in Suffolk Superior Court, XZENIYEJU CHUKWUEZI (D.O.B. 4/4/91) of Roxbury was arraigned with first-degree murder for allegedly gunning down Soheil Turner as the younger boy ate a honey bun while waiting for his school bus. He was also charged with unlawful possession of the firearm that killed Turner. A Suffolk County grand jury indicted Chukwuezi July 1 after two months of extensive inquiry by Boston Police and Suffolk prosecutors.

Suffolk Superior Court Clerk Magistrate Gary D. Wilson accommodated a request by Assistant District Attorney John Pappas to hold Chukwuezi without bail; the defendant will return to court on July 23, when he is expected to appeal that decision. Chukwuezi has ben held without bail since his May 20 arrest.

Finally, Assistant District Attorney Cory Flashner appealed to Judge Rosalind Miller to hold JAMES A. WALKER, a.k.a. “GUNNA” (D.O.B. 9/9/86), without bail for the 2006 murder of Antoine Perkins. Flashner told the court that Walker – a known member of the Lucerne Street Doggz street gang – had targeted Perkins after robbing another person of marijuana in a transaction that Perkins had facilitated.

Walker was arrested yesterday amid an ongoing grand jury investigation and was at the time in federal custody on drug charges stemming from a Lucerne Street crackdown. Miller granted Flashner’s request and told the defendant to return to court with attorney James Budreau on Aug. 5.

“These were three different murders with three different sets of facts,” Conley said. “Three different families coping with loss felt their wounds reopen in three different courtrooms. Each one, though, was in the company of a dedicated prosecutor and a team of experienced detectives committed to finding justice on their behalf.”