Updated

Police arrested a 22-year-old man Friday suspected of a bludgeoning attack in a blood-splattered Las Vegas home that left a woman and her daughter dead and her husband in critical condition, authorities said.

Bryan Clay was arrested on child abuse charges and is expected to be formally charged Saturday for the murders of 38-year-old Ignacia Martinez and 10-year-old Karla Martinez, police said late Friday night.

Officers went to their Robin Street home April 16 and found the bodies after the woman's 9-year-old son arrived at school saying that his mom and sister were dead. A 4-year-old boy was also found unharmed in the house.

Arturo Martinez, 39, the husband and father, was critically injured in the attack and remains hospitalized with head injuries.

"At 5 p.m. this evening, expedited DNA results came back from the lab linking Clay to the crime scene in both the Robin Street case and another violent sexual assault of a woman prior to the murders," police said in a statement.

Police said Clay is also a suspect in the April 15 sexual assault against a 50-year-old woman.

Fifth-grader Karla Martinez was sexually assaulted during the brutal attack, police said.

Authorities found the girl and the mother beaten to death with a blunt instrument in separate bedrooms.

In the days after the attack, the two boys were in protective custody with the Clark County Department of Family Services.