Massachusetts man sentenced to life in prison for killing wife while in process of divorce

Middlesex District Attorney Marian Ryan and Lexington Chief of Police Michael McLean have announced that Hongyan Sun has been sentenced to life in prison without the possibility of parole by Justice Patrick Haagan after a jury found him guilty of Murder in the First Degree on February 3, 2023 in the Lowell Superior Court.

On May 29, 2019, the body of Shen Cai, 49, of Lexington was found in the early morning, staged in her car, on a public street a short distance away from the home she shared with her husband, the defendant. The medical examiner subsequently determined that the cause of Cai’s death was homicide due to mechanical asphyxiation. The defendant later admitted to having a physical altercation with his wife on the 28th and was observed with numerous injuries consistent with a significant physical struggle, corresponding to the victim’s injuries.

During the ensuing joint investigation by the Lexington Police Department and the Massachusetts State Police Detective Unit assigned to the Middlesex District Attorney’s Office, over 15 search warrants were obtained and executed, resulting in the arrest of the defendant on June 5. 2019.

It was determined that the defendant and Cai had been in the midst of divorce proceedings at the time of the murder. On May 28, the defendant physically assaulted the victim, causing blunt force trauma to numerous parts of her body before he ultimately strangled her to death.

A review of surveillance footage allowed investigators to determine that the victim’s vehicle was staged within a short time window in the morning of May 29, 2019. It was also determined that the defendant went to work late that morning, giving him the opportunity to place the victim’s vehicle with her body staged as found on the public street by their residence. Examination of the GPS on the defendant’s phone also placed him in the location that covered both the residence and the spot where the victim was found. Forensic evidence was found at the scene, the defendant’s office, and on the victim’s body that also linked the defendant to the crime.

The prosecutors assigned to the case were Assistant District Attorney Suzanne Wiseman and Assistant District Attorney Megan McGovern. The paralegal was Elsa Ubel, and the Victim Witness Advocate was Susie Marshall.