An Arkansas couple were killed while hiking with their two young daughters in Devil's Den State Park, investigators said. Police were searching for a suspect.

Clinton David Brink, 43, and Cristen Amanda Brink, 41, were found dead Saturday at the park in Washington County in a suspected double homicide, Arkansas State Police said. The couple were hiking with their two daughters, ages 7 and 9, when they were attacked, state police said. Their daughters were not hurt and are being cared for by family members.

The couple's family released a statement that was provided by the Arkansas State Police on Monday night, saying: "The family is asking for privacy during this very difficult time as they grieve and learn how to navigate this new reality. They ask that if anyone has any information at all that will help the investigation, to please contact the proper authorities immediately. Clinton and Cristen died heroes, protecting their little girls and they deserve justice. They will forever live on in all of our hearts."

Police have not elaborated on how the couple were killed or provided more details on the attack.

Officials described the suspect as a White male wearing dark pants, a dark ballcap, sunglasses and fingerless gloves who also had a black backpack. He was believed to be wearing a long-sleeved shirt with the sleeves rolled up instead of a dark tank top that was originally reported. He was seen driving toward a park exit in a black, four-door sedan with a license plate partly covered by tape.

The car, possibly a Mazda, may have been traveling on State Highway 170 or State Highway 220 near the park in a rural, wooded area with limited cellphone service, police said.

State police released a sketch on Monday night of a man seen in Devil's Den State Park on Saturday, asking the public for help identifying him so police can question him.

Devil's Den is located near West Fork, about 136 miles northwest of Little Rock. The 2,500-acre park is known for its hiking trails and rock formations, and is a short drive from the University of Arkansas in Fayetteville and Walmart's Bentonville headquarters.

Investigators asked for potential witnesses to review their photos and videos from the park. There was no information about a possible motive.

Officials said the victims had recently moved to Prairie Grove, Arkansas, from another state. Hiland Dairy confirmed that Clinton Brink had transferred from its parent company, Prairie Farms Dairy, from South Dakota, and was scheduled to start his job as a driver delivering milk in the Fayetteville area on Monday.

Shea Lewis, secretary of the Arkansas Department of Parks, Heritage and Tourism, said rangers have stepped up patrols at Devil's Den.

"Our hearts are with the victims' loved ones during this incredibly difficult time," Lewis said in a statement Sunday. "The safety of our visitors and staff is our highest priority, and we are working closely with Arkansas State Police and various law enforcement officials as the investigation continues."

When CBS affiliate KFSM-TV asked why it took about six hours between officials receiving reports of the deaths and sending out a public statement, an Arkansas State Police spokesperson said the area where the suspected homicide occurred is remote. 

"It took time for our Special Agents to arrive on scene, locate witnesses, conduct interviews and collaborate information so we released the appropriate information," the spokesperson told KFSM.

The victims' bodies were taken to the Arkansas State Crime Lab, where the manner and cause of death will be determined.

The FBI's Little Rock field office is communicating with Arkansas State Police and is ready to assist with the investigation, FBI spokesperson Jessica Franklin told KFSM.

"We are praying for the family and friends of the victims, and know that law enforcement will not rest until the perpetrator is brought to justice," Arkansas Gov. Sarah Huckabee Sanders said in a statement.