TRENTON, N.J. (AP) — Two children found living in a 5-by-10-foot unit at a storage facility in New Jersey had been staying there with their mother for about a month, authorities said Friday.

Their mother, Sheena Johnson, 27, was arrested Thursday in Trenton on allegations that she slashed her ex-boyfriend's tires. As part of routine questioning in arrests involving domestic violence, police asked Johnson if she had any dependents and if so, where they were staying.

Trenton Police Lt. Mark Kieffer said an officer became suspicious when Johnson began to respond evasively. The woman told police she had two children, ages 5 and 10, and they were waiting for a bus with another person near a storage facility where she had rented a unit.

The officer drove to the facility in nearby Ewing and demanded the locker be opened. At first, no one would let him in without a search warrant.

Then he told them there might be children inside, Kieffer said.

When the officer opened the door, he found the children, along with a bare mattress, garbage bags filled with clothes, a suitcase, a backpack and other items strewn around the locker.

"It was deplorable conditions," Kieffer said.

Police said the children were examined at a hospital and found to be unharmed. They are now in state custody.

Johnson was charged with child endangerment by Ewing police. She also faces charges of criminal mischief, domestic violence and violating a restraining order over her arrest in Trenton.

Ewing Police Det. Sgt. John Stemler said one of his officers went to a nearby McDonald's to buy each child a Happy Meal. Stemler could not say what the children told police because their statements are part of the investigation.

Stemler said the storage facility is not being investigated.

A unit that size at the Ewing location costs up to $70 a month, according to its website.

Stemler was unaware of any past incidents where people were found living in the units.

Johnson remains held on $75,000 bail in Trenton. Police did not know Friday if she had hired a lawyer.