Matthew Clark was found Tuesday in his trailer at Spice Branch in Varney by family members. Reports said Clark was shot in the head and the abdomen and had been covered with a bed comforter.
The baby, he said, is in extreme danger and an amber alert has been issued.
"From a couple of statements we got from neighbors, they said that in the past she had threatened (to harm the baby)," Smith said, noting that there had been problems between the husband and wife recently. "We are trying to fit the pieces in together and we need to find her to actually see what's going on and to make sure the child is safe."
Smith said deputies have not received any tips on Crystal Clark's and the baby's location nor have they had any contact with the woman.
Smith said the Federal Bureau of Investigation has been called in to assist with the search for mother and child. He said the West Virginia State Police will be scanning the area from a helicopter in an effort to locate Crystal Clark and her daughter.
"The FBI is here helping us and we have the State Police helicopter down here now and we're going to do some aerial searches just in case she is here locally," Smith said.
Police are searching for Clark in other areas and states where she is known to have visited, including Tennessee and North Carolina, Smith said.
Crystal Clark should be considered armed and dangerous and, if spotted, should be approached with caution, Smith said.
"She is just a person of interest right now and we'd like to talk to her," Smith said. "Being the wife, we figure she can give us more details into what's going on."
Smith said he isn't sure if Crystal Clark has fled from police.
"We don't really know all the circumstances yet," Smith said. "We're trying to find her to see if she is on the run or possibly kidnapped. We don't know. We're not locking down on one avenue right now. We just want to find her and the baby and then go from there. We're trying to check all of her locations from North Carolina to Tennessee, where she's been in the past and where she's lived at."
Smith confirmed reports that the couple had been having marital problems and that Matthew Clark had threatened to take the baby to North Carolina.
The Mingo County 911 call came in yesterday around 1:30 p.m. and several police officers were on the scene from shortly thereafter until late Tuesday evening. Smith said the body was found by neighbors in the mobile home in bed and covered with a comforter.