Police in Aurora, Colorado are working to gain entry into the apartment of 24-year-old shooting-massacre suspect James Holmes.

Officials say they have managed to get past the first trip-wire, in an apartment that they believe contains at least several traps and incendiary devices.

“We have been successful in defeating the first threat,” said an official with police in Aurora. “We defeated a trip wire, and the first incendiary device.”

“This trip wire was set up to clearly detonate when somebody entered that apartment, and it was set up to kill that person,” she added.

There are several more incendiary devices still set up, according to police, who said a controlled detonation is not out of the question.

“In the second phase, this may include the controlled detonation of another triggering mechanism,” the police official said. “That is being assessed as we speak.”

Before the shooting, Holmes purchased four guns in the last two months, along with thousands of rounds of ammunition, according to police.

Police believe the guns were legally bought at local gun stores and online.

The four weapons used in the massacre include an assault rifle, while Holmes was also wearing body armour and a gas mask.

American President Barack Obama used his weekly radio address to reassure concerned citizens.

“This weekend I hope everyone takes some time for prayer and reflection, for the victims of this terrible tragedy, for the people who knew them and loved them, for those who are still struggling to recover,” Obama said.

Holmes is due to make his first appearance in court Monday, where he will face charges of murdering 12 people and wounding 58 others at a deadly movie theatre shooting in the Colorado suburb of Aurora.

The 24-year-old Ph.D student previously had no criminal record.

Justin Davis, who was sitting in the theatre next to where Holmes allegedly opened fire, saw bullets rip through the walls.

He says he hopes the community can find a way to move on.

“We should just forgive and we don’t know what he’s going through, you don’t know why he did it, we don’t know what was going on his life to make him do this,” Davis said.