Lexington man charged in killing of wife ordered held without bail

Hongyan Sun was arraigned in Concord District Court for the murder of his wife, Shen Cai.(Pat Greenhouse/Globe Staff)/Globe Staff

LEXINGTON — Police who interviewed Hongyan Sun after he allegedly murdered his wife last week in this affluent town noticed that he appeared to have been hurt in a violent clash, but he said he couldn’t explain the injuries, according to a police report.

The report was filed in Concord District Court, where Sun, 50, was held without bail on a murder charge in the slaying of Shen Cai, 49, his wife of about four years, whom he was in the process of divorcing. A not-guilty plea was entered on Sun’s behalf.

Cai’s body was found in her vehicle on Worthen Road in Lexington early on the morning of May 30. The state medical examiner’s office ruled her death a homicide by mechanical asphyxiation, according to the report. Police alleged her body was staged in a manner meant to “mislead law enforcement.”

Middlesex District Attorney Marian T. Ryan’s office said there was “significant trauma to the victim’s neck consistent with being strangled and trauma to her body and extremities consistent with a violent struggle.”

Sun admitted to police that he had a physical altercation with Cai two days before she was found, the report said.

Sun said his wife had bitten his finger during the fight. In fact, “his finger had actually been bitten off during the struggle, which Mr. Sun had concealed with bandages,” the report said. “Mr. Sun had multiple additional injuries to his body and extremities consistent with having a violent physical altercation.”

Sun said he didn’t know how he had been injured, the report said, and he gave conflicting accounts regarding when he had last seen his wife.

Cai had expressed concern for her safety before the murder, telling friends and her divorce attorney that her husband had a history of verbal abuse, controlling behavior, and one prior instance of physical violence, the report said.

“Ms. Cai also reported that her husband threatened to kill both her and her daughter from her previous marriage,” the report said.

“Ms. Cai became increasingly fearful of her husband in the days leading up to her death, and on May 27, 2019, told her friend that if she ever was found dead, it would be a homicide not a suicide.”

Cai was last heard from on the evening of May 28, when she talked with her divorce attorney about Sun hiding her personal items, the report said. That was the same evening she fought with her husband, according to the report.

Police obtained a warrant to search the couple’s home, near the spot where Cai’s body was discovered, and observed “potential biological evidence . . . placing the scene of that violent struggle” at the residence, the report said.

Authorities also discovered evidence that someone tried to clean up the crime scene, and Sun was seen throwing away shoes at his work, the report said.

The shoes were later determined to have blood on them, the report said.

Sun filed for divorce in September, citing an irretrievable breakdown of the marriage, court records show. The couple had met through mutual friends in 2013 and married two years later, according to divorce records.

Cai left her job in Shanghai as marketing director for Danone, the international food and beverage company, to move to Massachusetts with her daughter and marry Sun, who lived in Waltham at the time, records show.

Sun’s next court hearing is slated for July 30.