Texas EquuSearch joined the search for four children whose father took them along on a multi-county chase with law enforcement officers.
Noe Soto-Aranda's pickup truck was found in Sealy, but he and the children remained missing Friday.
Officers said someone saw the woman, Luz Lacayo, and her husband, Soto-Aranda, 31, fighting on the Southwest Freeway Wednesday evening and called for help.
Lacayo said Soto-Aranda wanted her to drive faster, but she refused because their four children were inside the vehicle.
"I was driving because he was drinking," Lacayo said.
Police followed their white Ford pickup truck. When Lacayo pulled over on Bissonnet and the Southwest Freeway, she tried to get her kids out of the pickup truck.
"The husband jumped in the driver's seat, took off with the kids," Houston Police Sgt. Ron Borza said. "We just want to talk to him and make sure the kids are safe."
"I don't know what got into him, but maybe because he has some problems," Lacayo said.
Police said Soto-Aranda caused one accident in Stafford.
Officers and deputies followed but lost him somewhere in the Richmond/Rosenberg area. About 9:30 p.m. Wednesday, DPS spotted Soto-Aranda's truck and chased it along Oilfield Road and FM 3013. The truck was found a short time later in Sealy in Austin County.
Texas EquuSearch is looking for the children in the area where the pickup truck was found.
Investigators believe Soto-Aranda and his children slept at a home in the 5200 block of F.M. 3013 on Wednesday night.
"There's a travel-trailer behind the house that looks like people slept there and there was an ice cream container with four spoons in it," said Sgt. Matt Ochoa with Texas Department of Public Safety. "This is a very good sign."
Ochoa said that evidence leads them to believe the father and his four children are still together and that Soto-Aranda is trying to take care of them as best he can.
"Our main concern is the safety of the children," Ochoa said.
Deputies said he broke into the travel-trailer behind the house after abandoning his vehicle in Sealy.
"Somebody ripped open the wall and made entry that's where we found a pallet and it looks like small people had been sleeping," Ochoa said.
After sleeping there for the night, Ochoa said Soto-Aranda is believed to have stolen a car from a nearby home. A 2011 red Hyundai Sonata was missing from the driveway with a Texas tag of CV2X779. That is the vehicle police are looking for and believe Soto-Aranda and his four kids are driving.
Soto-Aranda is the biological father of the four young children -- one girl and three boys between the ages of 3 and 8 years old. Friends said his wife is expecting their fifth child in a few weeks. Police said Soto-Aranda and Lacayo got into a fight at a hospital earlier in the day.
Police said Immigration and Customs Enforcement agents are also looking for Soto-Aranda. He was charged with domestic abuse in 2009 in connection with a case that apparently involves his mother-in-law.
Soto-Aranda is facing three new charges in connection with Wednesday's chase -- assault of a family member, endangering a child and evading arrest.
Police said an Amber Alert was not issued because the case does not meet the criteria. Soto-Aranda does not have a history of violence against the children and they are his biological children.
Investigators said an Amber Alert could be issued later if warranted.
If you have any information or see the missing vehicle, call Houston Police Missing Persons Unit at 713-731-5223.