Brooke Ann Slocum and Charles Gerard Oppenneer

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GRAND RAPIDS, MI – A missing pregnant woman has been found dead in the trunk of a vehicle that was driven by the suspect in her boyfriend’s homicide, and police say the accused killer committed suicide while in a car chase with authorities Thursday night.

The deaths of 18-year-old Brooke Slocum and the suspect come after Wyoming police found her boyfriend, Charles Oppenneer, dead in Gezon Park on Wednesday, July 16.

Wyoming Police Chief James Carmody said investigators were in the process of preparing a search warrant for a Wyoming home when the homicide suspect, who has not been identified by police, left the residence.

Investigators observing the home alerted patrol officers, who stopped the suspect’s vehicle on Burton Street near Burlingame Avenue SW. The suspect drove off on Burton Street when officers approached, Carmody said.

The man's vehicle later crashed onto the railing of the northbound U.S. 131 entrance ramp off Burton Street about 9:15 p.m. Carmody said the man was found dead from a gunshot wound that appeared to be self-inflicted. They discovered Slocum's body in the trunk after confirming the suspect's death.

Police have not disclosed the link between the suspect and Oppenneer and Slocum. Carmody did not take any questions at a Friday morning press conference and the cause of death of each of the victims has been withheld by investigators.

Investigators have planned a 9 a.m. news briefing to provide another update on the homicides.

A car abandoned near the edge of Gezon Park initially led officers to search the area, finding Oppenneer's body about noon Wednesday. Oppenneer and Slocum were last seen leaving her Grand Rapids apartment on Saturday night.

Brooke Slocum

She was eight months pregnant with Oppenneer's child. The couple planned to move into an apartment together.

Brooke Slocum’s relatives last saw her on July 11. They spent hours searching Gezon Park on Thursday.

Greg Slocum, her father, accompanied by crying relatives, looked for any sign of her, even though relatives didn’t know if she had ever been there and were unaware of what police would find later that night.

"I just had to come down for peace of mind - look around, see if I could find anything myself, but it’s kind of hard when you’re looking for a needle in a haystack and don’t even have a point of origin,” he said.

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As Greg Slocum walked the trails between large fields and wooded areas, he said he initially hadn't realized how expansive the park is.

Greg Slocum feared his daughter could have been abducted, but that she would fight.

"She’s definitely a survivor. If she could get away, I know she would’ve called me. She would’ve said, 'Come get me,' and I would’ve been there in a second," he said during the search.

Angie Jackson covers public safety and breaking news for MLive/The Grand Rapids Press. Email her at ajackso3@mlive.com, and follow her on Twitter.