Green Lake County, Wisconsin, Sheriff's Police released this photo of an pot-growing operation they reported discovering in the garage of William S. Carlson, who was allegedly killed by Matthew Watson in River Forest on July 12. (Photo provided by the Green Lake County Sheriff's Department)

By Jean Lotus

Contributing Reporter

A Wisconsin man shot and killed in River Forest on July 12 had a significant marijuana-growing operation in his garage in Green Lake County, the Green Lake County Sheriff's department said in a press release on Monday.

On July 12, as part of the River Forest homicide investigation, the Green Lake Sheriff's Department was contacted by the West Suburban Major Crimes Task Force (WESTAF) to help investigate the shooting death of William S. Carlson, 60.

A sheriff's deputy went to Carlson's home on Kahl Road around 7 p.m. No one was home, but the deputy smelled raw cannabis coming from the garage and noticed vent pipes blowing from the garage and windows blacked out.

After obtaining a search warrant, the sheriff's department reported recovering more than 25 live plants and more than 7.5 pounds of marijuana. Carlson was identified as a potential suspect in the ownership of the growing operation, according to police.

"The Green Lake County Sheriff's Office is currently working with River Forest, Illinois, officials to determine any other facts and circumstances associated to the homicide," the news release said.

Carlson reportedly was shot in the chest at close range with a shotgun by Matthew Watson, 24, in a home in the 100 block of Lathrop Avenue. Watson also is believed to have shot his mother, Susan Watson, 59, who remains hospitalized in stable condition.

Matthew Watson was killed by police after reportedly firing his shotgun as they responded to a 911 call made by Watson's mother. Two police officers suffered non-life threatening wounds in the shootout with Matthew Watson.

Neither law enforcement agency would comment on the relationship between Susan Watson, Matthew Watson and Carlson, but neighbors told Wednesday Journal Susan and Calrson were a couple.

The River Forest police have not released any information about the shooting other than a statement the afternoon of July 12. Deputy Chief James O'Shea characterized the shooting, which injured two officers, as an "ambush."

The Illinois State Police Public Integrity Task Force is investigating the death of Matthew Watson.