DNA leads to arrest in '02 slaying

QUINCY -- Because he was convicted in August 2004 of assault and battery with a machete in Hingham, Carlos Seino was required to submit a DNA sample to State Police under a law that had been passed six months earlier.

Last Thursday, the State Police crime lab matched Seino's sample to blood found in the pocket of Daniel DeCosta, who was robbed and beaten to death four years ago while walking home from a bar in Quincy.

Yesterday, Seino, 46, dressed in a gray sweater and pajama pants, was arraigned in Quincy District Court and charged with robbery and murder. He pleaded not guilty.

``Absent the work of the crime lab, this case may have never been solved," State Police Lieutenant Colonel John Kelly said yesterday during a press conference at the Norfolk district attorney's office. There were no witnesses to the murder and detectives were stymied.

``We were left with a situation where we were hoping for a lucky break, but what you have here is a scientific break," Norfolk District Attorney William R. Keating said.

According to prosecutors, DeCosta was with friends at Sully's Lounge on Chestnut Street on the night of Aug. 3, 2002, and cashed two checks -- one from his job as a custodian at Quincy City Hall was for $500, the other was a government check for $103.

DeCosta was gregarious, buying drinks for patrons, and playing Keno and darts. He also flashed ``wads" of money, according to witness statements contained in court records.

During the evening, DeCosta bought a drink for a woman, later identified as Seino's ex-girlfriend. At approximately 12:40 a.m., Seino showed up at the bar and talked with his ex-girlfriend and noticed DeCosta's bankroll, assistant prosecutor Tom Finigan said.

DeCosta left the bar at about 1 p.m. and headed to his nearby rooming house. His body was found at 7 a.m. the next day.

Seino submitted a DNA sample last summer and it was uploaded into CODIS, an FBI national DNA database, in March.

Joanne B. Sgueglia, the technical manager of forensic biology at the State Police crime lab in Sudbury, said the lab is backlogged with DNA samples and has been ``playing catch-up for the last few years" trying to enter the samples into CODIS.

For the past six months, Seino was staying with his girlfriend at her parents' home in Randolph. He was arrested there Monday night.