IOWA, UNITED STATES (REUTERS) - Hundreds gathered at the University of Iowa on Wednesday (Aug 22) to remember fellow student Mollie Tibbetts, who was reported missing in July and whose body was found in a nearby cornfield this week.

Ms Tibbetts' brother, Jake Tibbetts, asked students and staff to hold on to the good memories they have of her.

A 24-year-old man, Cristhian Bahena Rivera, described as an illegal immigrant from Mexico, was charged with murder on Tuesday, after he led detectives to the body of a woman, believed to be that of a college student who went missing a month ago, in an Iowa cornfield, state investigators said.

Ms Tibbetts, 20, who attended the University of Iowa, disappeared in July while jogging.

US Homeland Security officials said Rivera is an "illegal alien", said Mr Rick Rahn, special agent in charge at the Iowa Division of Criminal Investigation. He added that investigators believe Rivera is from Mexico.

President Donald Trump referred to Rivera's being in the country illegally during a campaign speech for a Republican US Senate candidate in West Virginia. Illegal immigration has been a lightning rod issue for Mr Trump, who has repeatedly said illegal immigrants were responsible for many violent crimes.

Rivera was identified in security video taken from a camera outside a house in Brooklyn, Iowa, where Ms Tibbetts was last seen alive, investigators said.