ALBANY — Police don’t know exactly what led a 22-year-old Albany man to shoot his former girlfriend in the head as she drove them down Erie Street this past Sunday.

On Thursday afternoon, Acting Chief Robert Sears laid out what police had learned in the four days since emergency responders found Nahjayyah Daise, 21, of Albany, gravely injured at the intersection of Erie Street and Erie Boulevard.

Only minutes later around 3 p.m., her ex-boyfriend, Larnell Kennedy, was hit and killed by an SUV as he tried to run across Interstate 90 near exit 6A.

The couple had an on-again off-again relationship but no known history of domestic violence, police said at a news conference at Albany police headquarters.

“There is no indication that anything like this was ever going to happen,” Sears said. “They did have their ups and downs during their relationship but nothing that would ever indicate something like this would happen.”

Sears said Kennedy shot Daise three times. At some point after that, he got out of the car as it continued down Erie Street and then chased after it, Sears said.

Kennedy eventually caught up to the car when it hit a utility pole. Sears said other drivers pulled over to see if the man needed help or someone to call 911.

“When the witnesses first came about, all they saw was the gentlemen chasing the car down the street. They had no idea what they were encountering,” the chief said.

He gave this account of how Kennedy ended up on I-90 just south of the crash. Witnesses said he tried to take Daise’s body from the front seat to the trunk. When he couldn’t manage to put her in the trunk, he got in the driver's seat and backed over her as he tried to escape. A witness boxed the car in and Kennedy got out. He ran up Erie Street and climbed an embankment to the interstate, scaled the fence and crossed several lanes of westbound traffic before being struck and killed by the eastbound SUV around exit 6A.

Witnesses were key to police piecing together the sequence of events that afternoon.

"We did get many different reports in the hour and hours after it happened," he said. "But once were able to talk to those witnesses, things became much more clear."

Police recovered the handgun they believe to be the murder weapon near his body. They did not release the caliber of the gun but said the serial number had been defaced.

Police said they have not determined why Kennedy ran onto the highway.

“Certainly, he could’ve been trying to commit suicide, but he also could’ve not seen the car because of the way the turn is there and there’s a concrete barrier,” State Police Maj. Robert Patnaude. He said a vehicle behind the one that struck Kennedy captured the collision on a dash camera.

Kennedy and Daise were pronounced dead at Albany Medical Center Hospital. Police released few details about the pair beyond that she had been arrested in May and charged with stabbing a man. That crime occurred outside the OTB in the Delaware Plaza in Bethlehem. She was charged with assault.