The FBI and Tennessee Bureau of Investigation have been called in to support local authorities with a “deeply saddening” inquiry where a mother, father, grandmother, and a 15-year-old were all found dead this week after officials began investigating an abandoned baby case reported earlier.

Local District Attorney Danny Goodman Jr., from the 29th Judicial District, informed Law&Crime on Wednesday that the baby from the abandoned child investigation, a 7-month-old, is related to the family, being the son of Matthew Wilson and Adrianna Williams, found deceased Tuesday around 8 p.m., along with the infant’s grandmother, Cortney Rose, and his maternal teenage uncle, Braden Williams, according to Goodman.

“TBI is interviewing individuals who may have information,” Goodman said, noting that “several people” are being questioned.

“This isn’t something that would just randomly occur that should worry the average person,” Goodman explained to Law&Crime. “This is a situation where I don’t think there’s a lot of public concern about a similar incident happening to someone else. There will be an explanation later on.”

Federal agents and TBI officers were on the scene Wednesday helping law enforcement with the “tragic” death probe after the bodies were located Tuesday in Lake County along Carrington Road in Tiptonville, TBI officials stated.

The abandoned baby investigation originated from finding Wilson and Williams’ 7-month-old child in a “random individual’s front yard” on Tuesday at approximately 3:10 p.m., according to the police. A “dark-colored minivan or a white mid-size SUV” reportedly left the baby in a car seat, which directed officers to Lake County and led to the bodies being discovered roughly five hours later after the authorities identified the infant’s parents, Goodman reported.

“TBI agents, with the assistance of the FBI and the Lake and Dyer County sheriff’s offices, continue to investigate the deaths of four individuals found Tuesday along Carrington Road in Tiptonville,” TBI Communications Director Josh DeVine told Law&Crime. “At this time, the investigation remains active and ongoing,” DeVine said.

Dyer County Sheriff Jeff Box posted a statement on Facebook saying Tuesday was a “deeply saddening day” for his community following the discovery.

“We are committed to uncovering the truth and ensuring justice is served,” Box said.

Lake County Sheriff Bryan Avery informed residents on his office’s Facebook page that the TBI was leading this case “with the highest level of diligence and professionalism” possible.

“This remains a very active and ongoing investigation,” Avery said. “Our thoughts and prayers are with the friends, families, and the entire community impacted by this tragic situation. We know this is a difficult time, and we stand with you.”

TBI officials would not say Wednesday whether any criminality was suspected or suspects being sought in connection to the death investigation, nor would Goodman. Police referred all requests for comment by Law&Crime to the bureau. The FBI did not respond to Law&Crime’s requests for comment.