(INDIANAPOLIS) -- Indiana authorities have made an apparent break in their investigation into who triggered the massive explosion that killed two people and leveled some of an Indianapolis neighborhood earlier this month.
"Our investigators are talking to individuals we have identified as potentially having relevant information," prosecutor Terry Curry said.
Earlier this week, ABC News learned that authorities now believe the Nov. 10 blast in the subdivision just south of Indianapolis that killed John and Jennifer Longworth was caused intentionally.
Police won't say who they are questioning, but cellphone video captured by Brad Horton and his girlfriend Whitney Essex shows a SWAT team descending on a mobile home park in southwest Indianapolis.
"These people came in tanks with people on top of them," Essex told ABC News.
The couple says their neighbor, Bob Leonard, was led away for questioning. Leonard is the brother of Mark Leonard, who is dating Montserrate Shirley, who along with Mark Leonard, lives in the home that exploded.
"It was pretty serious. They don't pull those [tanks] out for just anything," Horton said.
Much of the attention since the explosion has centered on Shirley and Mark Leonard, who lived at the house in the center of the blast area. The two ignored questions from reporters on Tuesday.
The couple says they were at a casino, and the home was empty when the explosion rocked the quiet neighborhood, killing the Longworths and damaging nearly 100 homes.
An attorney for Shirley and Mark Leonard said they are cooperating with police.
Overnight, prosecutors refused to confirm if they believe Bob Leonard is involved, or if they believe the blast was triggered by a remote.
"As we develop additional information, and identify individuals who potentially have pertinent information, we'll just pursue all those leads and that's exactly what we're doing," Curry said.
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