The police in Kansas City, Mo., said on Wednesday that they believed they had found the body of the man suspected of killing one person and wounding several others in a series of roadway shootings last week.

The suspect, Oscar Sanchez-Munoz, 22, committed five back-to-back roadway shootings on June 16, police said. The violence occurred just as Kansas City moved into the global spotlight as host of two World Cup matches at Arrowhead Stadium.

After the police had conducted a weeklong search for Mr. Sanchez-Munoz, his relatives contacted the police on Wednesday afternoon upon discovering what appeared to be a human body buried beneath clutter in the basement of his fire-damaged home in Independence, Mo. The police had already searched that home last week, a spokesman said.

Detectives arrived at the scene and confirmed the presence of a deceased person clothed in the same outfit Mr. Sanchez-Munoz had been seen wearing on the night of the shootings, the spokesman said.

“Detectives preliminarily believe this deceased person in the residence is Sanchez-Munoz,” said the police spokesman, Capt. Jake Becchina.

A medical examiner will determine the identity of the deceased person and the cause and circumstances of the death, police said. The medical examiner in Jackson County, Mo., could not be reached for comment on Wednesday night.

Last week, shortly after the shootings, police officers followed Mr. Sanchez-Munoz to his house in Independence and surrounded the property. During the ensuing standoff, a fire broke out inside the home.

Police later searched the property for Mr. Sanchez-Munoz but did not find him. A manhunt began, leading detectives across the city, through a cemetery and ultimately back to where they had started.

In the past week, the F.B.I. joined the hunt for the gunman, offering a reward of up to $25,000 for information concerning his whereabouts.

On Wednesday morning, the police combed through the wooded area surrounding the home in Independence and a neighboring cemetery, searching for clues.

Around 2 p.m., the breakthrough came. In the basement of the Independence home, beneath debris left soaked when flames were put out last week, family members “noticed the smell of decomposition” and phoned the authorities, the police said.

With Mr. Sanchez-Munoz now presumed dead, the police said they might never know the motive for the string of attacks he is believed to have committed. But they said that discussions with family members indicated that he had been experiencing a worsening mental health crisis in the days leading up to the shootings.

The police have not named the person killed in the attacks or the four injured victims. Of the wounded, one is a teenager and three are adults, the police previously said, including an Uber driver who was taking fans to Arrowhead Stadium before the World Cup match.

One of the adults was said to have life-threatening wounds.

There is no indication that the shootings were related to the World Cup in any way, the police said on Wednesday. The attacks had no “direct connection to or effect” on the tournament, they added.

Mr. Sanchez-Munoz was also wanted in an aggravated assault case in neighboring Kansas, the police previously said.