(NewsNation) —  After announcing there’s a serial killer on the loose Wednesday, Stockton, California Police Chief Stanley McFadden has revealed new information about the suspect.

According to McFadden, ballistic evidence links the murder of a man in Oakland last year to the recent killings of five Stockton men and the attempted murder of a woman. McFadden also says his department thinks the killer is on a “mission.”

“We don’t know what the possible motive is but we do know that this person of interest is on a mission,” Kevin Lincoln, mayor of Stockton, told NewsNation’s “Rush Hour” on Thursday.

“What I can say right now is the city is really stepping up — the communities are really stepping up. We’re getting over 100 tips a day that are coming in. These are leads that our police department can use and follow up on so that we can bring this individual or individuals to justice and off the street,” Lincoln said.

For now, a video of a slim man in dark clothing with an unusual gait is among the biggest clues police are working with —the man is said to be a person of interest.

The search for a possible serial killer has Stockton residents and much of central California on edge — with hundreds attending a community meeting Wednesday night.

“Came to find out what they know, if anything,” said one participant at the community meeting.

An expert on serial killers anticipated the police determination of a mission behind the murders.

There’s “a better than 50-50 likelihood (that) this individual has given himself a mission to rid the Stockton area of homeless people. For whatever reason, he’s given himself this mission,” said Scott Bonn, an author and serial killer expert, said on NewsNation’s “Rush Hour” on Thursday.

While not all victims were homeless, Bonn suspects the killer assumed they were. And if the murder weapon has not changed hands, he believes the break between a killing last year in Oakland and the recent killings in Stockton is possibly due to incarceration, a job change or the process of relocation.

Unlike notorious killers such as Jeffrey Dahmer and Ted Bundy, this person is not driven by a desire for sex or control.

“What they’re really motivated by is the act of killing itself — not the process of killing, not the events leading up to it. There’s no attempt to get to know this person, spend time with them, it’s simply shoot and move on,” Bonn said.

However, true crime expert and author Jillian Lauren disagrees. Lauren told “Rush Hour” on Thursday that she “would think of it as sexual.”

“I think this is a sexually motivated killing in the sense that it’s about power and pleasure, whether or not there is a sexual act involved,” Lauren siad.

There is a $125,000 reward in this case, which comes amid an overall increase in violent crime in Stockton.

“The people of Stockton, we will get through this. And we will get through it together,” Lincoln said at a news conference.

With a possible serial killer at work, residents are discouraged from being out alone, especially in the dark.

“He’s going to kill again and probably kill again pretty soon,” Bonn said.

Each victim has been shot dead while alone at night. Five of the murders, all in Stockton, have taken place over the last five months.