The 44-year-old is considered "extremely unsafe", the sheriff's office said.
Marks, 44, faces three pending murder charges, the Montgomery County Sheriff's Office said in a tweet.
The Montgomery County Sheriff's Office and the Conroe Police Department are searching for an escaped prisoner considered extremely unsafe, who fled during a prisoner transport.
Marks was arrested in MI last month on a Bell County, Texas, charge alleging that on August 21, he broke into Scott's home in Temple, which is about 60 miles north of Austin.
Marks, who has not been charged in their deaths, was jailed in MI awaiting extradition for allegedly breaking into Scott's home back in August, according to the television station.
He's suspected in three killings, including the deaths of his former girlfriend Jenna Scott and her friend Michael Swearingin, who were last seen January 4, according to the station.
Duke Professor steps down over controversial email to Chinese Students
The school did not say whether it identified the two faculty members who allegedly spoke to Neely about the students. Neely, meanwhile, also included a personal note in DeLong's email to students, apologizing directly for her actions.
Two women were arrested in MI on charges related to Marks.
Marks is wanted in connection to the murder of his ex-girlfriend Jenna Scott and her friend Michael Swearingin. The Washington state woman had accused him of domestic violence.
Maya Renee Maxwell, 26, is charged with tampering or fabricating physical evidence with the intent to impair, a third-degree felony. Pease went missing in March 2009 and Marks got custody of their son.
An arrest affidavit said Maxwell, who became a person of interest because she last saw Swearingin's auto, admitted she took the 2016 Hyundai Genesis to Austin and left it there to hide it from law enforcement agencies.
Ginell McDonough, who is Marks' wife and the mother of two of his two children, is jailed in Muskegon County, Michigan, on an obstruction of justice charge. His last fight was in September of previous year.