Police are investigating how long Leticia Peralez, the mother of the 4-year-old boy who drowned in the Jordan River Friday, left her son unattended, police said Monday.

"Children sometimes act fast, and there's nothing you can do to stop these type of tragedies," said Murray Police Lt. Dee Rowland. "If that's the case here, we won't do anything to add to the suffering of the mother. But at the same time, we need to look at all the evidence and gather as much information as we can."Peralez's son, Josue Peralez, drowned after he fell into the river while feeding some ducks with his older brother from the banks in Winchester Park, 6400 S. Winchester St. (1050 West). Search crews didn't find the Midvale boy's body after two days of dragging the river.

Peralez, 28, had left the children unsupervised when Josue fell into the Jordan's swift-moving currents. Ceaser Peralez, 5, saw his brother fall into the water and disappear, police said.

Peralez originally told police that she left the children to go to the bathroom. She's changed her story, saying she left to go visit with a friend in a nearby parking lot, Rowland said.

"Her frame of mind was pretty emotional when we first got there, and we'll take that into account," he said. "She may not have had a complete recollection about what she had been doing. All she knew was her little boy was in the river."

Police are trying to determine how much supervision she was giving the children, Rowland said. She told investigators that she was gone only a "couple of minutes." Officers are investigating to see if that's the case.

"We're really interested in the time frame and the standard of care she was giving the kids," he added. "We're trying to find out everything we can about those two things."