Doan Bui often rode his bicycle from his Sudan Street apartment to fishing spots on Castle Island or near the John F. Kennedy Library and probably was heading home Friday after some late-night fishing, neighbors said.

He never made it. Authorities say the 63-year-old Dorchester man was struck by a speeding pickup truck on Morrissey Boulevard and thrown a significant distance, instantly killing him. The driver, identified by police as Michael D. Ahern, a 46-year-old cafe owner from Dorchester, was “clearly intoxicated” but stopped to call 911 from his cellphone, authorities said.

“That was the only correct ­decision he made that night,” Patrick Devlin, a Suffolk County prosecutor, said during Ahern’s arraignment Monday in Dorchester Municipal Court on charges of motor vehicle homicide and operating under the ­influence of alcohol causing death.


Ahern appeared despondent as his attorney, Jeffrey K. ­Clifford, pleaded not guilty on his behalf, with Ahern’s family sitting nearby. He was ordered held on $25,000 cash bail.

Ahern is listed as proprietor of the Sweet Life Bakery and Cafe in Lower Mills, which recently opened, and as a partner in the Ledge Kitchen and Drinks restaurant, also in Lower Mills.

Family and friends of the alleged victim covered their faces as Michael Ahern (not shown) was arraigned on charges of motor vehicle homicide.
Family and friends of the alleged victim covered their faces as Michael Ahern (not shown) was arraigned on charges of motor vehicle homicide.Aram Boghosian for The Boston Globe/Globe Freelance

Ahern told authorities he had one drink at a downtown Boston bar, but state troopers who responded at 12:30 a.m., to the scene, near Malibu Beach, said Ahern appeared drunk. Another trooper who responded to Boston Medical Center, where Ahern was taken at his request, also stated in his report that Ahern appeared inebriated.

Trooper Thomas D. Canning wrote in the report that because Ahern had a lawyer, he did not question him about the crash. Instead, he asked for identifying information and observed the defendant move about the hospital room, where he was being examined by medical staff. “I did not ask him about the accident. I detected a strong odor of intoxicating beverage coming from his person,’’ ­Canning wrote. “I observed his speech to be noticeably slurred and his tongue was thick and pasty. . . . I observed Michael to be noticeably unsteady as he walked.’’


Another trooper reported that after examining Ahern’s 2011 Ford F-150 truck, he concluded the vehicle was traveling at 50 miles an hour when Bui was hit; the posted speed limit is 30. There was no sign of braking on the roadway, the trooper concluded.

In court, Ahern’s attorney described the case against ­Ahern as “relatively weak.’’ He said State Police noted that ­Ahern’s eyes were bloodshot but failed to report that the air bag deployed, or that Ahern was wearing eyeglasses when the air bag hit his face.

Jake Wark, spokesman for Suffolk District Attorney Daniel F. Conley, said no breathalyzer test was given at the scene ­because Ahern requested to be taken to the hospital and getting him there took priority. ­Despite troopers’ observations that Ahern appeared intoxicated, no breathalyzer was administered at the hospital. Wark said that even without the voluntary breathalyzer test, the case against Ahern will be supported by evidence, including the troopers’ observations.

Ahern, who had invoked his right to counsel, was allowed to go home. Because Ahern’s vehicle was seized and authorities felt he was not a flight risk, Wark said, he was not arrested until Sunday night, when authorities had built their case.

According to the defense and prosecution, Ahern ­received a 20-year suspended sentence in Suffolk Superior Court in 1989 for an arson conviction, the details of which were not immediately available.


Records show that since 1985, Ahern has received multiple citations for failure to stop, speeding, and accidents, in several towns and cities. In 1992, his license was revoked as a ­habitual offender but reinstated two years later.

The Registry of Motor Vehicles suspended his driver’s ­license indefinitely as a result of the fatal crash, said a Registry spokesman. Ahern is due back in court Nov. 21.

Brian Ballou can be reached at bballou@globe.com.