(CNN) When the suspected Golden State Killer drove into a Hobby Lobby parking lot in April, investigators were waiting nearby. As he walked into the craft store, it gave them a perfect chance to collect a secret DNA sample.

Police swabbed the driver's side handle of Joseph James DeAngelo's car, according to arrest and search warrants released Friday.

Authorities sent it for testing and matched it to semen recovered at some of the Golden State Killer's crime scenes, the arrest warrant said.

The DNA collection at a public parking lot in Roseville, California, became a crucial turning point in the decades-old search for the suspect in the killings.

The documents unsealed by a California judge after a motion from news outlets provide a glimpse into detectives' work in the days leading up to the suspect's arrest.

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