Fort Smith police on Friday continued to investigate what they have called a "suspicious" death of a former Fort Smith Public Schools substitute teacher following an arrest in connection with the incident.

The body of William J. Dubois Jr., 72, who reportedly taught in the school district for three decades, was discovered during a welfare check around 4:30 p.m. Thursday inside a duplex in the 1800 block of South Greenwood Avenue. Detectives have determined Dubois' death was not due to natural or self-inflicted injuries and arrested one suspect who was not identified Friday tied to the case.

Police on Friday afternoon were "having to follow a number of leads" in relation to the incident, said police spokesperson Aric Mitchell. Mitchell on Friday did not say whether detectives have determined if Dubois' death was a homicide.

Mitchell did not disclose the arrestee's suspected charges or relationship to Dubois on Friday. He also did not disclose the circumstances leading up to Dubois' death or how police found the suspect, adding that giving out such information could intrude on detectives' investigation.

Police on Thursday afternoon taped off the yard of the duplex with crime scene tape as detectives walked in and out of the house. Officers and detectives were still on scene at 11:00 p.m. Thursday.

Dubois taught at Fort Smith Public Schools from 1973-2003 as a substitute teacher and worked part-time in the athletic department, said Fort Smith Public Schools Executive Director of Communications Director Zena Featherston Marshall. Marshall said Dubois taught at Northside High School while she attended school there.

"It's a sad day," Marshall said of Dubois' death.

Mitchell on Friday could not estimate when he would be allowed to release more information to the public, but anticipated the situation would "make a lot more sense in a day or two."