Incarcerated person arrested in connection with 3 Long Beach cold case killings

A man who is already serving multiple life sentences in state prison confessed to his role in three additional Long Beach killings, according to authorities.

In a news release, the Long Beach Police Department said 39-year-old Glenn Cox confessed to multiple murders and an attempted murder to Avenal State Prison personnel in December 2023. Subsequent investigations and evidence linked him to three homicides and an attempted homicide, police said.

Cox was previously convicted of murder and attempted murder charges.

He was arrested on Oct. 17 on suspicion of three additional counts of murder, three additional counts of attempted murder, and two additional counts of possession of a firearm by a person with a prior felony conviction.

The LBPD released the following details about the new incidents, which may be gang-related:

• "On Dec. 20, 2004, at approximately 11:15 p.m., officers responded to the 100 Block of East Pleasant Street to an unknown trouble call. Upon arrival, officers contacted four victims with gunshot wounds. A male adult victim was determined deceased at the scene. Three other male adult victims were transported to a local hospital, where one succumbed to his injuries and two others were treated for non-life-threatening injuries. The decedents were identified as Carlos Serrano, a 22-year-old resident of Long Beach, and Jermy Kershaw, a 23-year-old resident of Long Beach."
• "On Feb. 16, 2007, at approximately 12:05 a.m., officers responded to the 1700 Block of Cherry Avenue regarding a shots call. Upon arrival, officers contacted a male adult victim on the sidewalk with multiple gunshot wounds. The victim was determined deceased at the scene by Long Beach Fire. The decedent was identified as Dino Marks, a 31-year-old resident of Long Beach."
• "On Aug. 26, 2007, at approximately 3:54 p.m., officers responded to the 1000 Block of East Pacific Coast Highway regarding a shots call. Upon arrival, officers contacted a male adult victim with gunshot wounds to the lower body. Long Beach Fire personnel responded to the scene and transported the victim to a local hospital where he was treated for non-life-threatening injuries. The preliminary investigation indicated that the victim was on a bike when he was shot by a male adult suspect."