As the search for Maine mass shooting suspect Robert Card intensifies, authorities said Friday that they've received over 530 tips and leads.

The shelter-in-place order remains in effect in the cities of Lewiston, Auburn, Bowdoin and Lisbon, and there will be an ongoing conversation each day, authorities said.

Divers will be a "major focus today," authorities said, adding, "We have a lot of other irons in the fire."

Meanwhile, police are continuing their work at the two mass shooting sites, the bowling alley and the bar, authorities said.

"We are going to be processing every square inch of these facilities," authorities said.

The suspected gunman -- identified as 40-year-old Robert Card -- has been a U.S. Army reservist since December 2002, the Army said. He has no combat deployments.

Card's sister told investigators she thought Card might have been looking for an ex-girlfriend at the shooting locations, law enforcement officials briefed on the investigation told ABC News.

The suspect appears to have "interacted with conspiratorial content" online, information provided to law enforcement shows. Topics he engaged with included but were not limited to: concerns about a financial crisis/stock market, LGBTQ+ issues, gun rights and commentary about Democratic public officials, including President Joe Biden.

A law enforcement source with direct knowledge tells ABC News that Robert Card had affiliations with the two locations he allegedly targeted.

An ex-girlfriend is connected to one of the locations. According to the source, "We don’t think this was completely random."

The suspect also appears to have been fairly thoughtful about eluding police. He left behind a cellphone that authorities have recovered apparently suspecting it could be tracked.

-ABC News' Pierre Thomas

A large number of police vehicles that had surrounded a property tied to suspect Robert Card on Thursday have departed.

The search at this location seems to have gone quiet with most of the authorities having left the scene.

A source familiar with the search in Bowdoin tells ABC News there is no expectation the suspect will be apprehended at that location tonight.

The source said this search and the dramatic accompaniments were part of standard procedure for safely carrying out a search warrant.

Police will be doing this repeatedly as they work to retrieve evidence. They say they’re being thorough by tracking down every lead.

U.S. Rep. Jared Golden, (D-ME), announced that he was changing his policy against an assault rifle ban during a news conference with other Maine congressional leaders Thursday evening.

Golden was one of five Democratic House members who voted against a ban in 2022. Although the bill passed 217 -213, it did not move forward in the Senate.

Golden said the shooting has made him change his stance and will now support any measures in Congress that ban assault weapons.

"I ask for forgiveness and support as I seek to put this end to these terrible shootings," he said.

Sen. Susan Collins, (R-ME), told reporters that although she wanted to see more gun control reforms, such as a ban on high-volume magazines, she did not support an assault rifle ban.

Although Collins said she didn't know the circumstances as to how the suspect, who has had reported mental health issues, was able to commit the shooting, she said more should have been done.

She cited the state's "yellow flag" law, which gives law enforcement the authority to request a court to remove firearms from someone who has mental health problems.

"It certainly seems that on the basis of the facts that we have, the yellow flag law should have been triggered," she said.