The search for a missing Texas mother of four stretched into its third week as authorities said they arrested the business partner of the woman’s husband, who is currently behind bars on charges of assaulting his wife shortly before she went missing.

Texas Department of Public Safety officials said Tuesday they took James Valle Cotter, 65, into custody on a charge of tampering with evidence after linking him to Suzanne Simpson’s Oct. 7 disappearance outside her San Antonio home.

Mrs. Simpson, 51, was last seen having a physical altercation with her husband, Brad, who police said was “grabbing her upper torso area to gain control of her body.”

A neighbor told police that they later heard screaming coming from some woods nearby and witnessed Mr. Simpson’s truck leave the area about an hour afterward, according to local NBC affiliate WOAI-TV.

The latest turn in the case came with the arrest of Mr. Cotter, who partnered with Mr. Simpson to manage a janitorial company before the two were sued for underpaying invoices to a contractor.

Authorities accuse him of physically tampering with evidence that could affect the investigation into Mrs. Simpson’s whereabouts.

Barbara Clark, Mrs. Simpson’s mother, said she knew the couple had gotten into a physical confrontation once before, but told the TV station that such incidents were not “part of their life, or his behavior, and I’ve known him a long time.”

The husband was arrested Oct. 10 on charges of assault and unlawful restraint. He was also charged federally for illegal gun possession when authorities found an unregistered gun in his home during a search.

Mr. Simpson has remained in jail ever since, but police said he has not cooperated with their investigation.

Attempts to find the missing woman guided state and local authorities to a landfill, but police said they found no evidence of Mrs. Simpson at the dump.

• Matt Delaney can be reached at mdelaney@washingtontimes.com.